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Full text of "Viking Sewing Machine 6000 Series Technical Briefing"

TECHNICAL 
BRIEFING 



VIKING 



INTRODUCTION 

This Technical Service Manual has been written to meet the ever increasing requests for 
knowledge by Viking technicians. This manual endeavors to thoroughly cover the sec- 
tions listed below: 

1. Setting Tools and Gauges 

2. A Technical Briefing of The Viking Sewing Machine 

3. Removing the Machine Covers 

4. Inspecting Parts for Damage 

5. Checking the Noise Level and Machine Speed 

6. Electrical Checks and Adjustments for the 6570 

7. Service Checks and Adjustments 

8. Component Removal and Installation 

9. Component Repair 

10. Electrical Wiring of Terminal Blocks and Foot Controls 



The sections 3,4,5,6 and 7 are meant to be followed in sequence when doing a full service 
on a Viking sewing machine. 

In section 7, SERVICE CHECKS AND ADJUSTMENTS, the first page of each adjustment 
explains the requirement and adjustment procedure for the latest series of machines. If 
the adjustment differs from model to model you will find the correct instructions for that 
particular machine on a following page. 



STITCH FORMATION 

The primary function when sewing is to 
join two pieces of fabric with thread. 
When sewing by hand one thread is 
used. However, this requires that the en- 
tire needle must go through the fabric. 
When sewing by machine, two threads 
are used instead, which are intertwined, 



thereby avoiding the necessity of draw- 
ing the whole length of thread through 
the fabric. 




The needle in its 
lowest position 



2.5 




The stitch formation on a domestic 
(household) sewing machine is done in 
such a way that the needle, with the 
thread, passes through both layers of 
fabric down to its lowest position, then 
the needle raises 2.5 mm. The thread at 
this stage is not stretched and, due to 
the friction occurring between the thread 
and fabric, a ioop is formed in back of 
the needle. This loop is caught by the 
point of the shuttle and drawn round the 
whole shuttle. 

When the thread has passed the lowest 
point of the shuttle the thread take-up 
iever starts gathering the thread. The 
loop reduces and the upper thread pulls 
the lower thread up to the stitch plate. If 
the* upper thread tension and lower 
thread tension are set correctly, an in- 
tertwining of the lower and upper 
threads occurs between the two layers 
of fabric. Thus, a stitch is formed. 




The movement of the needle going from 
its lowest position until the point of the 
shuttle catches the loop is called the 
loop-forming distance. At this point it is 
particularly important that the fabric is 
held flat against the stitch plate. If the 
fabric should be pushed down through 




The center of 
the needle 



Stretch fabric 





the hole in the stitch plate by the needle 
and pulled up again when the needle 
goes through the hole in the presser foot, 
the loop-forming distance will be cor- 
respondingly reduced and can be so 
small that no loop is formed at all. 
However, the machine is adjusted in 
such a way that the point of the hook 
shall always be able to catch the thread, 
even if the loop is practically non- 
existent. There is a scarf in the needle, 
above the eye, for this purpose. The point 
of the hook is approximately 5/100 mm in 
front of the remainder of the side of the 
Ffl £ r/c shuttle. When the needle is above the 
level of the stitch plate, the feeding of 
the fabric takes place and then ceases 
immediately after the thread take-up 
lever has drawn up the whole thread 
loop. During this time the hook revolves 
one turn*in order to be correctily posi- 
tioned to catch the thread when the nee- 
dle next completes a loop-forming 
distance. 



The loop-forming distance 




SEAM FORMATION 



The type of stitch formation just described is used on practically all domestic sewing 
machines and the machines then differ in the way they form seams. The simplest seam is 
straight stitching, where the machine feeds forwards or backwards with the same stitch 
length along a straight line. Husqvarna used to manufacture straight stitch machines, 
but this manufacture has now been discontinued. When sewing zigzag seams, the needle 
moves at right angles to the direction of feeding the same length, every other stitch to the 
left, the other to the right. Regarding zigzag sewing machines, we have the model 6170. 
If the movement of the needle varies in size and direction, according to a certain pro- 
gram, seams of varying appearance will be produced. We have this type of seams on all 
specified machines, the first of which is model 6170. It is also possible to vary the 
feeding in size and direction, thereby obtaining additional variation possibilities. These 
type of seams are to be found on the machines 6270, 6370 and 6570. 
Besides straight stitch and zigzag, the seams are usually divided into utility and 
decorative seams. Utility seams are adapted to a certain sewing operation, e.g. hemming 
of a skirt of a certain type of fabric such as tricot, jersey, etc. Utility seams give in such 
cases a certain elasticity and memory. 
The decorative seams are intended to decorate a garment or piece of work. 




Zig-Zag 



SHUTTLE SYSTEM 



As mentioned earlier, the stitch forma- 
tion is made by means of a needle and a 
shuttle system. Even if all domestic 
machines have the same type of stitch 
formation, the construction of the 
shuttle system can vary. 
In the original type of construction, the 
shuttle was designed in such a way that 
it, together with the lower thread, moved 
in a straight line. However, today, all 
shuttle systems are designed so that the 
shuttle rotates around the bobin with the 
tower thread. 

Shuttle systems can be divided into two 
specific types, namely those where the 
shuttle rotates on a horizontal level 
(drop-in bobbin), and those where it 
rotates on a vertical level, parallel with 
the needle (Viking). 



The Viking Husqvarna shuttle system is 
designed with a vertical, rotating hook 
freely suspended between the driver and 
the shuttle cover. This eliminates any 
risk of loose threads getting caught up in 
the shuttle. It also requires no lubrica- 
tion. This system has been used in our 
sewing machines since the fifties and 
we are still the only manufacturer using 
this design. 



v 









DESIGN OF THE VIKING SHUTTLE SYSTEM 



The driver is shaped like a dish and made 
of sound diminishing plastic. The shuttle 
lies in this dish 






Driver 



Shuttle 



Shuttle cover 



The shuttle (hook) is made of steel sheet, 
shaped in two halves which are soldered 
together. A rather soft quality of material 
with low carbon content is used, thereby 
facilitating punching. The two halves are 
brazed by placing a copper thread bet- 
ween two flat surfaces and the parts are 
fixed in relation to each other. The cop- 
per melts when heated to 1,1000°, 
spreads out in the space and solders the 
two halves together, these are then mill- 
ed and thereafter heat treated in an at- 
mosphere containing carbon monoxide. 
The material absorbs the carbon and can 
be tempered. The result is a detail with 
very hard surfaces, while the core is still 
softer and ductile. 



The tip of the shuttle which must absorb 
carbon from four sides becomes hard all 
the way through. The bobbin case is also 
shaped in steel sheet, which is then 
tempered and chrome-plated. 
A lot of work is devoted to the shaping 
and finishing of the shuttle and bobbin 
case. Machining is, of course, done as 
much as possible but manual operations 
cannot be completely avoided. Both of 
these parts go through about 150 opera- 
tions before they are finished. 



The tip of the shuttle 




continued 

The shuttle cover is made of plastic and 
must be freely suspended, e.g. be able to 
move both axially and radially. Since the 
shuttle is freely suspended between the 
driver and shuttle cover, it must move 
evenly to avoid problems with high noise 
level. It is, therefore, necessary to devote 
a great deal of work when manufacturing 
the gear for the shuttle and the other 
parts, so that the path of the thread 
through the shuttle causes as little fric- 
tion as possible on the parts. 




Shuttle cover 



Shuttle cover 



Bobbin case 



Bobbin 




Free-arm shaft 



Shuttle gear 
Shuttle transmission 



8 



BEARINGS 

The bearings for the upper main shaft and the lower main shaft are mounted in sleeves of 
sintered steel and the bearing arrangements in cast iron (steel) machines are produced 
by precision drilling. Straight, cylindrical sleeves are pressed into the precision-drilled 
holes. A very high degree of precision is required and tolerances here are less than 2/100 
mm, i.e. less than a third of the thickness of a human hair. 

Very high precision demands are also made on the shafts. The production tolerance of 
the diameter Is 6/100 mm and this has been attained by grinding the shaft. Measuring is 
done by using compressed air; the air must pass through a ring, in which the shaft is in- 
serted. The resistance against the air constitutes a diameter measurement. 




continued 

Non-lubrication is attained by the fact 
that the bearing sleeves are oil- 
impregnated. To produce sinter steel 
sleeves, powder metal is pressed in a 
tool into a detail of the required shape. 
This detail is then heated .in a nitrogen 
atmoshpere to such a temperature 
whereby the small particles of metal 
melt on the surface and adhere to each 
other. This method ensures that very 
high precisioned, stable parts are pro- 
duced but the material is porous. It is 
these pores that act as reservoirs for oil. 

The rotation of a 
shaft in a sintered 
steel sleeve will 
generate some 
heat on account 
of the friction, the 
wall of the sleeve 
is also subjected 
to pressure. Con- 
sequently the oil 
gets warmer and 
expands, i.e. is 
forced out of the 
pores in the sleeve 
and lubricates just at the point where it 
is best needed. When the machine is 
then switched off and the bearing sleeve 
cools, the oil returns to the pores. 




To ensure maximum operational reliabili- 
ty we use a special oil. This oil has to 
meet very stringent demands regarding 
its consistency when in contact with the 
surrounding atmosphere and on its 
viscosity properties when returning to 
the pores after each time the machine is 
used. This type of bearing has been 
tested by us during a period of 12 years, 
under very stringent conditions from the 
point of view of climate and operation. 
They have met these very high demands. 
Sintered metal is used for the bearings, 
as is the case with many other parts in 
the sewing machine mechanisms, where 
good bearing properties are an advan- 
tage. 



10 



THE SEWING MACHINE FRAMES 



The sewing machine is built up around a frame which can be designed in several different 
ways. However, in all versions, the needle moves down through the stitch plate to the 
shuttle, where the stitch is formed. There is a space to the right of the needle which 
should be designed so that the part of the garment which is on the right-hand side of the 
seam can be moved forwards. A necessity for good sewing results is that the frame 
is stable and that the nee- 
dle is always correctly 
positioned in relation to 
the stitch plate and shut- 
tle. A flat-bed machine is 
generally designed in such 
a manner that the upper 
arm is screwed to the bed. 
The same applies to most 
free-arm machines when 
the upper arm is screwed 
to the free-arm. The frame 
of Husqvarna machines is 
cast in one piece, e.g. the 
upper arm and free-arm 
consist of one piece only. 




11 



continued 

THE FRAME OF HUSQVARNA 

SEWING MACHINES 

Husqvarna manufactures sewing 
machines in two materials, namely of 
cast iron (steel) and aluminum alloy. 
The cast iron frames are produced by 
means of shell moulding, where the 
mould is built up of phenol-impregnated 
sand. The mould is then placed in a 
frame. By using this method, it is possi- 
ble to produce homogeneous castings 
with thin walls and smooth surfaces. In 
addition to this, the whole of the outside 
of the machine is ground, to ensure ab- 
solutely smooth painted surfaces and a 
high grade of adherence between the 
enamel and the iron. The mould can only 
be used once. 

The aluminum alloy is cast, without- 
pressure, in a steel mould with a core of 
sand. The core is destroyed but the steel 
mould can be used for 20,000 castings. 
This casting is also machined on the out- 
side, mainly by milling. By using these 
methods, it is possible to produce bodies 
of rather complicated and closed form 
and the castings have good damping pro- 
perties. 

All these frames are cast in one piece, 
e.g. the free-arm and the rest of the 
machine body consist of one piece only. 



PAINTING OF THE FRAME 

The frames are painted in an elec- 
trostatic plant, where the paint is 
pumped up to a rotating plate. The paint 
particles are charged to a voltage of 
80,000 volts and scattered into the air by 
the centrifugal force. The sewing 
machine frame is grounded and 
therefore attracts the charged paint par- 
ticles. This method produces very even 
distribution of the paint, even over com- 
plicated surfaces. All details are painted 
two or three times and hardened for 20 
minutes between each painting at a 
temperature of 120 °C. 




o 



o 



Painted 



Casting 



Coated 



Milled 



12 




Thread tension spring 



THREAD TENSION 

LOWER THREAD TENSION 

The lower thread 
tension is con- 
trolled by the 
thread tension 
spring on the bob- 
bin case, the 
thread tension is 
set in a spring- 
balanced fixture 
to a rating of 22 g. 
(This setting is 

not altered during the assembly of the 
machine). This operation is done to at- 
tain the highest degree of uniformity bet- 
ween the bobbin cases. A problem in this 
connection is the varying qualities of 
thread which cause different resistance. 
All machines were previously set with 
cotton thread. Now synthetic thread is 
used. Cotton thread is affected by the 
humidity in the air and varying frictional 
conditions occur in different climates. 
Synthetic thread does not absorb 
moisture, but even synthetic threads 
vary, depending on how they were 
treated before being wound on a thread 
spool. 



13 



continued 



UPPER THREAD TENSION 



The upper thread tension is controlled at 
the thread tension device. This is com- 
pletly built into the face plate and 
located in a way that the thread can 
naturally be threaded between the 
thread tension discs. Even here, the 
thread tension intensity is pre-set so that 

Thread tension knob 

Thread tension spring 

Thread tension washer 





Thread 



a certain rating can be obtained at the 
red dot on the thread tension knob. This 
tension is adapted to balance the lower 
thread tension when sewing cotton 
fabric of normal quality and with the 
thread supplied with the machine. 
We have endeavoured to have the 
machines set as uniformly as possible 
and a thread tension which is as ver- 
satile as possible. However, there are 
many personal opinions regarding 



thread tension. Fabrics used on certain 
markets can also differ from what we 
consider most usual. Unfortunately it is 
a fact that many customers feel bound to 
use the setting obtained at the red dot. 
Under certain conditions it can, 
therefore, be appropriate to alter the ten- 
sion at the red dot. This is easily done by 
altering the outer ring on the tread ten- 
sion knob. 



F 



7 — 

E 6 ~ 



1 



14 



HOLDING THE FABRIC IN PLACE 



It was pointed out when talking about 
stitch formation how important it is to 
hold the fabric flat during the movement 
of the needle. To attain this, presser feet 
are used, which press the fabric against 
the stitch plate. Different sorts of 
presser feet are used for different types 
of sewing and they have, therefore, been 
designed to be easy to change. They con- 
sist of an attachment and a sole, where 
only the sole is exchanged. The presser 
foot pressure can also be adapted to dif- 
ferent types of sewing or fabric. By turn- 
ing the knob at the front of face plate 
cover, the spring for the presser bar 
pressure is influenced, either to increase 
or reduce the presser foot pressure. 





15 



THE DRIVING OF THE MACHINE 
AND ELECTRIC SPEED REGULATION 



ELECTRIC DRIVE 



POWER TRANSMISSION 



The sewing machine is driven by an 
electric motor which is rubber mounted 
in the base piate to prevent sound from 
the motor being propagated in the 




machine. It is double insulated and con- 
nection to a wall socket is done by 
means of a two-wire system and a uni- 
versal plug. It is supplied with built-in 
electrical components making the whole 
equipment radio and TV-suppressed 
according to applicable international 
regulations. 

As far as electric motors are concerned 
they are the absolute best quality to 
ensure that the machine operates reli- 
ably and to reduce service costs. 



The power is transmitted from the motor 
by means of a cog belt to a reduction 
gear, which is adjustable and allows a 
reduction in the speed of one-fifth. There 
is a V-belt between the reduction gear 
and the main shaft, enabling a certain 
elasticity in the transmission. However, 
there is a built-in belt tension device to 
eliminate slipping and to compensate for 
possible wear of the V-belt. This consists 
of two belt idlers; it sets itself auto- 
matically to increase the belt pressure 
against the belt wheel when the needle 
meets a harder resistance. 



V-belt 

Automatic belt 
tension device 




Motor 



Cogbelt 



16 



continued 



Synchronization between the main shaft 
and the free arm shaft is done by means 
of a chain belt. The seam former is driven 
by a worm gear which works on the main 
shaft, white the shuttle gear is driven by 
a bevel drive. 



A lot of work has been devoted to making 
the machine as reliable as possible, both 
as regards the structural design of the 
machine and the manufacture of the 
various parts. 




V-belt 



Cog wheel 



Reduction gear 



17 



SPEED CONTROL 



There is a main switch on the belt guard 
which controls the electric current to the 
motor, printed circuit and light bulb. As 
long as the electricity is disconnected 
there is no risk of the machine starting if 
the foot control should be inadvertently 
depressed. The lamp can be used as an 
indicator as to whether or not the elec- 
tric current is connected. 
The speed of the machine is regulated by 
a foot control, which is connected to the 
electronic equipment built into the 
machine. The foot control is designed to 
give support to the whole foot. When the 
control is depressed, a low current 
passes through it, regulating the speed 
of the motor. 



Full current is available all the time to 
the motor and as very little of the current 
is consumed by the foot control, there is 
an extremely low energy loss and no 
buildup of heat. 

The electronic equipment converts the 
alternating current from the power 
supply to pulsating direct current by 
means of the components D A and D 2 
(diodes) and this in turn regulates the 
motor via Ty, and Ty 2 (thyristers). There 
are also circuits which give the motor 
more current if the needle meets harder 
resistance. Due to these circuits it has 
been possible to greatly increase the 
needle power and thereby the penetra- 



DIODES D,,D 2 




THYRISTORS TY|,TT 2 




.,i,QP; v - 
iMilil 



-F=1 





— 1 


1 
. 1 

1 








1 

1 
^=J 1 


1 



n 



o 



i 



i i ~i 

o o o 
o o o o o 




&c*Hu. ., ... 

nuif^liol' °!!o!l.iU' 





18 



continued 



tion capacity. Compared to a machine 
with resistance control the increase is 
doubled or trebled at low speed. This 
enables the machine to be kept at an 
even, low speed, independent of the 
load. 

SETTING THE STOP-RIGHT 
POSITION OF THE NEEDLE 

To enable the finished work to be 
removed from the machine without the 
lower thread being hindered by the 
shuttle, it is necessary that the needle is 
at its upper position. In the same way the 
needle must be free from the fabric when 
changing a seam or movement in button- 
holing. In some cases it may also be 
important that the needle remains at its 
lowest position, e.g., if a sudden change 
of direction in a seam is necessary. In 
these cases it is a great help if the 
needle stop-right position can be set and 
this may be done by using the stop-right 
pushbutton, located on the belt guard. 
By pressing in the upper part of the push- 
button the needle will stop at its highest 
position and when the lower part is 
pressed in, the needle will stop at its 
lowest position. When the pushbutton is 
at the center position, the needle will 
stop at any position. 



The stop-right function is attained by a 
metal screen, which is built into the 
handwheel, actuating a magnetic 
switch. When the foot control is released 
the regulated current cuts out, and only 
the current through the electronic circuit 
conveys the needle to the required stop- 
right position. If the needle meets such 
hard resistance that the machine jams, 
the current to the motor cuts out auto- 
matically after 5 seconds. 



19 



OTHER MATERIAL 



Most of the small details (parts) of the 
sewing machine are made of steel or 
steel alloys with different grades of 
tempering. However, quite a lot of the 
details in the mechanisms are made of 
die-cast aluminum. In addition, there are 
some details which must have good 
bearing properties and wear resistance, 
which are made of different sorts of 
plastic. 

On the subject of plastic, it is important 
to distinguish between the type of 
plastic used in design details and the 
type used for inexpensive packing and 
throw-away wrappings. The construc- 
tional plastics have completely different 
properties and are considerably more 
expensive. If a detail, e.g., a cog wheel or 
a programmer, is made of plastic, it must 
have advantages over metal — e.g., a 
cog gear will function more smoothly 



and quietly; a cog gear or programmer 
will have more wear resistance. If the 
programmer is made of metal it will wear 
much quicker, even when using the best 
special steel, as long as the properties 
are not changed completely by means of 
an oil bath or the like. 



Reduction gear 

^ Acetal, glassfiber 

reinforced 




Nylon (good friction 
characteristics 
together with 
acetal) 



20 



continued 



Husqvarna manufactures many details 
in their own plastics machines but a 
good deal of the larger details are 
bought from specialist manufacturers. 
The processing is done by spraying the 
molten material into closed steel tools, 
which have a cavity corresponding to the 
shape of the detail. After a certain 
cooling time, the tool is opened and the 
detail is in its final shape. Sometimes, 
even certain plastic details must be 
machined to attain sufficient precision. 
The programmers are bought from a 
specialist manufacturer as workpieces 
and then machined, first in the hole and 
the end face. The cams for the needle 
bar movement are cast in the final 
measurement with a precision of ±% 00 
mm. The cams for the feeding movement 
must be of even higher precision. These 
are, therefore, machined by scraping 
with a precision of ±% 00 mm. The steer- 
ing worm gear and the gear for the 
shuttle are machined on the outside and 
also the cog is cut by machining. 





Acetal (good 
wear resistance, 

low friction) 



Special 
steel 



21 



PATTERN MECHANISM 




The most 
advanced 
mechanism 
in the 
machine is 
the pattern 
mechanism, 
which is actually a programme works for 
the position of the needle and for deter- 
mining the size and direction of feeding. 
When turning the knob, both cam follow- 
ers should be lifted from the cams and 
the fixed cam and programmer moves 
axially. To facilitate the setting, a cog 
gear has been designed, so that the knob 
is turned half a turn between each index- 
ing. 

The movement of the fixed cam is acti- 
vated from the main shaft and is syn- 
chronized to the movement of the 
needle. The cam followers then sense 
the different radius positions on the 
respective cam and transfer the move- 
ment to its mechanism. 



Cam follower for 

the reverse lever Fixed 

arm cam 




Cam follower for 
needle bar movement 



22 



continued 

MOVEMENT OF THE NEEDLE BAR 

The pattern mechanism is built up in a 
frame with horizontal shafts which 
support the fixed cam and cam follower. 
The cam follower for the movement of 
the needle bar has its point of suspen- 
sion slightly to the left of the fixed cam. 
By means of the stitch width knob, the 
position of the draw rod in the guide of 
the cam follower can be set. 



As the fit-up point of the draw rod is in 
front of the turning center of the cam 
followers, there is no side movement of 
the needle bar, i.e., the machine sews 
straight seams. When the draw rod is 
moved downwards, a side movement of 
the needle bar is obtained. The curve of 
the cam then determines the reciprocal 
size of the sideways deflection of the 
needle bar. 



Link 




Stitch width cam 



23 



MOVEMENT OF THE FEED DOG 



There are two eccentrics behind the wheel of the synchronizing belt. By means of a 



connecting rod and a feeding shaft, one of 



Guide on 
stitch length 



Camcurve 



Guide in 
reverse 

position 



the eccentrics produces the height 
movement of the feed dog, and this is 
always constant. The size and 
direction of the lengthwise movement 
of the feed dog, which is produced by 
the other eccentric, can be altered. 




24 



continued 

This depends on how the guide in the 
stitch length mechanism is set. This 
guide is set by means of the stitch length 
knob and the machine then sews a seam 
with constant feeding. However, if the 
pattern mechanism is set at a feeding 
pattern, the cam follower for the auto- 
matic feeding is affected so that the size 
and direction of the feeding changes 
between each stitch. This adjustment 
must take place when the feed dog is 
under the level of the stitch plate. It is, 
therefore, important that the seam 
former is synchronized in relation to the 
movement of the feed dog, i.e., over the 
main shaft. 

It is possible to make adjustments on the 
pattern mechanism for the lifting height 
(retraction) of both cam followers, for the 
center needle position, and the relation- 
ship between the left hand needle posi- 
tion and the zigzag position. In addition 
it is possible to adjust the relation 
between forward and reverse feeding 
when sewing patterns. The machine can 
be adjusted in such a way that the 
needle returns to the same position as it 
had previously after a part of the pattern. 



25 



STITCH LENGTH MECHANISM 



As mentioned under the description of 
the pattern-mechanism the lengthwise 
movement of the feed dog, i.e., the stitch 
length, is effected by the setting of the 
guide in the stitch length mechanism. 
This guide is set by means of the stitch 
length knob which has two axial curves 
which decide the angular position of the 
guide. The foremost curve is coupled at 
normal sewing and the rear curve works 
as a stop when the reverse feeding 
button is depressed. Reverse sewing 
using the reverse feeding button is 
usually used for locking the thread, so 
the curve is not completely symmetric 
with the curve for forward feeding and 
the button will not lock. By means of an 
adjusting nut in the reverse feed button, 
the relation between forward and reverse 
feeding can be adjusted. This adjust- 
ment nut is where the buttonhole column 
equalization is adjusted. 



Guide in 
reverse 

position 



Guide on 
stitch 
length 




Camcurve 




Guide in 

forward 

position 



Reverse 
button 



Stitch length dial 




26 



BUTTONHOLE MECHANISM 




Follower for 
radial cams 



The stttch width is set from the button- 
hole mechanism and also the different 
buttonhole moments. The main shaft of 
the mechanism is equipped with two 
radial curves at the rear part. One is a 
spiral curve which makes continuous 
adjustment of the stitch width possible. 
The other one, which is coupled when 
the knob is pulled out, i.e., the button- 
hole automatic, when coupled has four 
different positions. These are adapted to 
produce suitable stitch widths for the 
different steps when sewing button- 
holes. 




27 



continued 

There is an axial curve nearer to the 
knob, which is coupled when the button- 
hole automatic is used, and this deter- 
mines the direction of the feeding when 
sewing buttonholes. 

There is also a press-button below the 
buttonhole automatic, for disconnecting 
the feed dog, i.e., drop-feed button. 




Radial cams 



Axial cam 



Main shafi 



28 



REMOVING COVERS 

FOR MACHINE SERIES 70, 60, 40 

I. FACE PLATE SHELL 

Push latch (A) downwards and 
remove the lower part of the face 
plate shell from the machine. It's then 
possible to lift the shell upwards, 
releasing it from the upper fastening 
screw. Remove the shell. 

II. ARM SLEEVE 

Release the stitch plate by pressing 
key (A), the remove. Drop the feed 
teeth. Remove screw (B) and slide the 
arm sleeve off the open arm. 




COMMENT 

When installing the stitch plate, put the 
arm sleeve on and moderately secure the 
screw (B). Install the stitch plate and 
check to see that it pops up when key (A) 
is pushed. Remove plate and secure 
screw (B). 




29 



REMOVING COVERS 

FOR MACHINE SERIES 70, 60, 40 

III. BACK COVER 

Take away the programmer and 
remove the two screws (A). Snap off 
the bobbin winder cap and remove 
screw (B) which is underneath the 
bobbin winding thread guide. Lay the 
machine on its back and remove the 
two screws (C). Remove the back 
cover. 



COMMENT 

On the latest series machines the 
two screws (C) will be absent. They 
have been replaced by a nylon stud 
and an integrated locking tab which 
fits under the terminal block. 

NOTE This is a good time to open 
the inspection plate (D). 




30 



REMOVING COVERS 

FOR MACHINE SERIES 70, 60, 40 

IV. BELT GUARD 

70 Series 

Rotate the handwheel until the 
thread take-up lever is in its lowest 
position. Remove the mounting 
screw in the middle of the hand- 
wheel and then remove the hand- 
wheel. Remove screw (A) and the 
belt guard can easily be taken away. 

NOTE Notice the eccentric adjust- 
ment screw in the bottom of the 
belt guard. Turning this adjust- 
ment screw will align the belt 
guard parallel to the frame of 
the sewing machine. 



60 and 40 Series Machines 

First, pull off the handwheel, then take hold of the belt guard and see if it will 
come away. On some earlier models it may be necessary to lay the machine on its 
back and remove the Phillips screw in the upper right corner. Then it will be 
possible to remove the belt guard. 

V. PATTERN SCALE 

Lift out at the upper left corner, and 
firmly shift the scale to the right to 
snap it off. 

NOTE The pattern scale must be re- 
moved to make it possible to 

adjust the needle positions, i.e., centering the zigzag in the stitch plate 
and centering the needle front to back in the stitch plate. 





31 



REMOVING COVERS 

FOR MACHINE SERIES 30, 20, 10 AND EARLIER MODELS 



I. FACE PLATE SHELL 

30 Series 

The latch (2) located under the lower 
edge of the face plate shell should be 
drawn downwards and the lower part 
of the shell lifted out from the 
machine. The cover can now be lifted 
upwards, so that it releases from the 
upper shoulder screw. 



COMMENT 

Screw (1) which secures the edge of the 
back cover should now be removed. 





FACE PLATE 

10 Series 

Open the cover and push in catch (1). 
This is best done with the tip of a screw- 
driver. Lift the cover up and remove it 
from the machine. Loosen the Phillips 
screw securing the release tab (20 series 
only). 



32 



REMOVING COVERS 

FOR MACHINE SERIES 30, 20, 10 AND EARLIER MODELS 



II. ARM COVERS, 

UPPER AND LOWER 

Remove the three screws (16) that 
hold the upper (18) and lower (22) arm 
covers on. Lift up on the right side of 
the upper cover, then slide it off to 
the left. Slide the lower cover to the 
left and away from the free arm. 



COMMENT I 

On some models, screws (16) 
come in two different lengths. 
Observe if this might be the case, 
and if so, remember which arm 
sleeve hole they go in. 



COMMENT II 

By removing screws (19) the stitch 
plate can be removed. The feed 
teeth are now available to clean. 




33 



REMOVING COVERS 

FOR MACHINE SERIFS 30, 20, 10 AND EARLIER MODELS 



BACK COVER 

Remove the programmer from the 
machine. Loosen and remove screw 
(1). Slide the back cover to the left 
and remove. 




IV. BELT GUARD 

The handwheel (1) is attached to the 
pulley by two springs (2). Pull the 
handwheel off. If necessary, insert 
two screwdrivers (between the hand- 
wheel and belt guard) and with equal 
pressure pry the handwheel off. 
Remove screw (3) and screw (4). The 
belt guard can now be taken away. 

NOTE The distance sleeve (5) is now 
loose and should be put with 
the belt guard. 



34 



REMOVING COVERS 

FOR MACHINE SERIES 30, 20, 10 AND EARLIER MODELS 

V. MOTOR COVER 

The motor cover (1) can be taken away after removing the two screws (6). 
COMMENT I 
Remove the inspection plate cover (7) by removing the two screws (8). 

COMMENT II 

Remove the cover (9) for the lower motor brush by removing screw (8). 




35 



THE STITCH PLATE 

REQUIREMENTS 

The stitch plate must not be damaged in 
any way. Particular attention should be 
made regarding damage or unevenness 
around the needle hole. 

ACTION 



E3EB- 



D 






Exchange the damaged stitch plate. 

COMMENTS 

A stitch plate not level around the needle 
hole opening will affect stitch formation, 
usually resulting in skipped stitches. 
Also, needle strikes and burrs on the 
stitch plate will snag material. 



41 15 628-01 





OU 



; 



^1 11 555-01 



37 



PRESSER FOOT 

REQUIREMENTS 

There should be no damage to the thread 
slot and no scratches or burrs on the 
underside of the presser foot. 

ACTION 

Exchange the presser foot if any damage 
is noticed. 

COMMENTS 

How the fabric is held between the 
presser foot and stitch plate plays an 
important role in stitch formation. 
Damage to the underside of the presser 
foot or the thread slot directly affects 
stitch quality. 



Upper 
side 



383 









Upper 
side 


* CM 

— J * ' 





















—J 










2 

-4 



Under 
side 



Zig-zag presser foot 41 1 1 383-01 



t < 

H 

I— «, 



Under 
side 



Utility stitch presser foot 41 14 512-01. 



38 



THE FEED TEETH 

REQUIREMENTS 

The upper side of the feed teeth (10/1) 
must not be damaged in any way. The 
feed teeth should be free of any lint, fluff 
and pieces of thread. 

ACTION 

Faulty feed teeth should be exchanged. 
Dismount the stitch plate, remove the 
screws (10/2) to exchange the feed teeth. 
The new feed teeth must be aligned 
parallel to the slots of the stitch plate. 

COMMENT 

When examining the feed teeth look 
closely at all four corners to determine if 
they are chipped or cracked. If damaged 
the material may be snagged. Also 
inspect the points of the feed teeth. If 
they have come in contact with the 
presser feet they may become dull. This 
will result in an uneven stitch length and 
puckering of the fabric. 




39 



THE SHUTTLE COVER 

REQUIREMENTS 

The inside and bridged area of the 
shuttle cover must not be damaged. 
When mounted on the shuttle posts the 
cover must have both axial and radial 
movement. 

ACTION 

Exchange the shuttle cover if it is 
damaged. Check to see that the shoulder 
screws and posts are not damaged. The 
shuttle cover clearance must be 
checked. 

COMMENT 

The inside of the shuttle cover is the 
support for the hook (shuttle), the 
bridged area on the shuttle cover 
supports the thread, so that the thread 
loop is formed on the correct side of the 
needle. If the bridged area is damaged 
the shuttle cover must be replaced. 





40 



SHUTTLE (HOOK) 

REQUIREMENTS 

The outer edge of the shuttle must not be 
damaged. The point of the hook must be 
sharp. 

ACTION 

If the outer edge of the hook is damaged, 
it may be honed or polished. If the hook 
point has been damaged it is not 
possible to make a correction; the 
shuttle should be exchanged. 

COMMENT 

If the hook point is damaged from 
contact with a needle without a scarf, 
the hook point will become rounded. 
Instead of picking up the lower thread, it 
will push it away, resulting in skipped 
stitches. When the hook point is properly 
shaped, it will pass between the needle 
and thread, completing the stitch. 




JtO 11 521-01 



41 



THE DRIVER 

REQUIREMENTS 

The outer edge of the driver and the 
surface of the driver against the hook 
must not be damaged, worn or uneven in 
any way which might hinder the passage 
of the thread. 



ACTION 

The damaged driver (9/10) should be 
exchanged. Turn the handwheel until the 
needle is in its highest position. The slot 
in the driver is now in the middle under- 
neath the feed teeth. Remove the three 
screws which hold the shuttle cover — 
lift away the shuttle cover and hook. 
Then remove the screws (9/11) in the 
driver, and exchange it for a new one. 
Note the position of the slot in the driver. 
The following adjustments must be 
checked: needle to hook clearance, 
shuttle cover clearance, timing of the 
hook. 



nruw 



w^f^— 




41 16 415-01 



COMMENT 

When exchanging the driver it is neces- 
sary to note the position of the slot in the 
driver and position the new driver in the 
same way. If this is not done it is pos- 
sible to install the new driver incorrectly 
which will cause the hook timing to be 
extremely out of adjustment. 



42 



STITCH PROGRAMMERS 

REQUIREMENTS 

The programmers or fixed cam must not 
be damaged in any way. 

ACTION 

Damaged programmers or fixed cams 
should be exchanged. 

COMMENT 

Examine each lobe of the programmers 
and fixed cam for grooves, nicks or 
burrs. The prongs on the programmers 
should be inspected. A broken prong 
may alter the stitch pattern formation 
and increase the noise level * of the 
sewing machine. 





43 



THE BOBBIN CASE 

COMMENT 

Thread lint and fuzz will adhere under the 
thread tension spring which causes the 
thread tension to change. Remove it by 
inserting a needle between the thread 
tension spring and bobbin case. 
Check the chrome around the bobbin 
case; there should be no peeling, tf this 
is noticed the bobbin case should be 
exchanged. 

If damage has occurred to the (32) latch 
spring, (31) latch, (34) the thread tension 
spring, (36) or the thread tension adjust- 
ment screw, the individual parts should 
be replaced. 




40 11 530-02 




30 31 32 33 34 35 36 



30) 41 

3D 40 

32) 40 

33) to 

34) 40 

35) 22 

36) 20 



10 601-01 

11 535-02 
11 536-01 
11 531-02 
11 781-01 
86 200-01 
71 211-01 



44 



UPPER MAIN SHAFT 

REQUIREMENTS 

The upper main shaft should run freely 
during its rotation. There should be no 
binding and no end play. 

ADJUSTMENT 



Set the thread take-up lever in the lowest 
position, remove the handwheel and 
then take away the belt guard. Loosen 
the stop screws 7/5 on the belt wheel. 
Turn the seam former with one hand in 
the direction of the arrow and push the 
belt wheel in the opposite direction. 
Then tighten the stop screws, commenc- 
ing with the one which is touching the 
milled plate (flat spot) on the arm shaft. 
Check that the arm shaft runs freely 
during the whole turn and that there is no 
axial play. When replacing the hand- 
wheel on model 6570, make sure that the 
thread take-up lever is in the lowest 
position and that the indication plate on 
the handwheel points upwards. 




COMMENT 

If there is end play in the upper main 
shaft there will be a knocking sound 
when zigzagging. 

To make this adjustment on models 21 
and 51 see the following page. 



45 



UPPER MAIN SHAFT 

MODELS 21, 51, 71, 7, ETC. 

REQUIREMENTS 

The upper main shaft should run freely 
during its rotation. There should be no 
binding and no end play. 

ADJUSTMENT 

Loosen set screws (1). Pull handwheel 
away from machine at the same time 
moving the thrust collar (2) against bear- 
ing. Then retighten the set screws. 

NOTE On the class 21-A, the thrust 
collar is located next to the 
handwheel. 

COMMENT 

It is possible the thrust collar is running 
too tightly against bearing. Loosen set 
screws to relieve pressure. 




46 



LOWER MAIN SHAFT 

REQUIREMENTS 

The lower main shaft should run freely 
during its rotation. There should be no 
binding and no end play. 

ADJUSTMENT 

Remove the inspection plate on the 
underneath of the base plate. Loosen the 
two (9/23) set screws in the positioning 
collar. Then press the chain belt in the 
direction of the arrow and the position- 
ing collar in the opposite direction. 
Tighten the set screws. 

COMMENT 

After making this adjustment be sure to 
check the play of the shuttle gears. 



9/23 




47 



SHUTTLE GEARS 

REQUIREMENTS 

By taking hold of the outside of the driver 
and rotating it left to right you should 
detect a slight amount of free movement. 

ADJUSTMENT 

The tolerance of the shuttle gears is 
adjusted by the position of the gear on 
the lower main shaft (free arm shaft) at 
the rear of the free arm. Loosen the two 
(9/2) set screws. Shift the position of the 
gear to the left to increase the tolerance, 
to the right to decrease. Tighten the set 
screw on the flat of the shaft first. 



Shuttle cover 



Bobbin case 



Bobbin 




>L— -J 



3L Shuttle gear 

Shuttle transmission 



COMMENT 

After each correction recheck the tangi- 
ble play of the driver. Also run the 
machine to determine if the noise level is 
within accepted tolerances. 



48 



MOTOR 

REQUIREMENTS 

The motor should run smoothly without a 
high noise level. 

ADJUSTMENT 

Check both carbon brushes by removing 
the brush cap (12). The carbon brushes 
should be at least 50% the size of new 
ones. It is recommended that both the 
carbon brush and spring be replaced. 
After installing new carbon brushes 
dress the commutator to seat the 
brushes. 

COMMENT 

The motor noise is affected by the load 
and the belt tension. If the motor 
deviates from normal check the tension 
of the cog belt. 

When replacing carbon brushes it is 
important to note the model of the 
machine. Starting with 6460 the carbon 
brush holder (16) was redesigned. Once 
the carbon has worn the holder will not 
allow the carbon brush spring (13) to ride 
the commutator. When ordering carbon 
brushes it is best to use the 40 16 295-01 
from 6460 and later models. For earlier 
models use the carbon brush 41 14 
934-01 which will repel from the commu- 
tator automatically when the carbon is 
worn. 




1-18 



19-25 





-16 
-15 
-14 

-13 
-12 



49 



COG BELT 

REQUIREMENTS 

The belt tension should not be so loose 
that it permits slipping when the 
machine is locked and the foot control is 
depressed. Tighter cog belt tension 
makes more noise. The belt should not 
be damaged. 

ADJUSTMENT 

The screws (14/8, 9) in the reduction gear 
holder are accessible by means of two 
holes in the large cog wheel (14/29). If 
both the screws are loosened, a certain 
adjustment is possible by moving the 
frame for the cog wheel one way or the 
other. Tighten the screws. 

COMMENT 

On models with electronics a cog belt 
that is set too tight will affect the speed 
and power of the needle stop-right posi- 
tions. The belt should have about 1 / 8 of an 
inch deflection when set correctly. 




50 



THE V-BELT 



REQUIREMENTS 



The belt tension should not be too tight 
or too loose. The slightest amount of 
slipping is permissible when the hand 
wheel is held firmly and the foot control 
depressed. 

ADJUSTMENT FOR 70 SERIES 
OR LATER MODELS 

The screws (14/8, 9) in the reduction gear 
holder are accessible by means of two 
holes in the large cog wheel (14/29). If 
both the screws are loosened, a certain 
adjustment is possible by moving the 
reduction gear up or down. 

COMMENT 

On the 70 series or later model machines 
with the dual idler, the tension of the 
V-belt is set at the same time as the cog 
belt. Notice the adjustment screws are 
the same for both. 

For models older than the 70 series see 
the following three pages. 




51 



THE V-BELT 

MODELS 6460, 6440, 6430, ETC. 

REQUIREMENTS 

The belt tension should not be too tight 
or too loose. The slightest amount of 
slipping is permissible when the hand- 
wheel is held firmly and the foot control 
depressed. 

ADJUSTMENT 

The tension of the belt is decided by the 
position of the motor bracket (14/11) and 
also the pressure the belt wheel has on 
it. Lay the machine on its back and 
loosen the screw (14/13) approximately a 
half turn. The tension of the belt can be 
altered if the screw is pressed down- 
wards. 

COMMENT 

The tighter the V-belt tension the more 
piercing power the needle has. But too 
much tension will cause the machine to 
bind, run slow and increase the noise 
level. 

To se the V-belt tension on models 10 
series (6010), 2000, 21, 19, 8 see the fol- 
lowing page. 




14/13 14/11 



52 



ADJUSTING V-BELT AND LOW GEAR 

MODELS 10 SERIES (6010), 2000, 19, 21, 8 

REQUIREMENTS 

The V-belt tension should be taut enough so no slipping will occur on the pulleys, but not 
too tight to cause binds. 

ADJUSTMENTS 

The spring (3) is set so that suitable belt tension is obtained when the guide plate (4) is 
attached in the vertical position. The position of the guide plate can be adjusted after the 
screw (5) has been loosened. On later machines the retainer (6) is made with an oval 
groove for the screw (7). A further possibility of increasing the belt tension is to loosen 
screw (7) and press down the retainer (6) until the desired belt tension is obtained. 




To set the V-belt tension on models 4310, 3310, 1310, 71, 51, 49 see the following page 



53 



THE BELT TENSION 

REQUIREMENTS FOR MODELS 
4310,3310, 1310,71,51,49 

When the correct belt tension is set, it 
should be possible to press together the 
two belt parts. 

ADJUSTMENT 

By turning the adjusting screw (1) clock- 
wise the belt tension will increase. By 
turning it counterclockwise the tension 
is reduced. 




54 



WORM WHEEL TOLERANCE 

REQUIREMENTS 

There should be little or no clearance 
between the worm wheel and worm gear 
on the main shaft. 

ADJUSTMENT 



Loosen the two set screws (7/2) on the 
worm gear. Loosen the set screw (7/3) on 
the positioning collar. The worm gear 
(7/1) will now move freely on the main 
shaft. By positioning the worm gear to 
the right it will increase the tolerance. To 
the left will decrease the tolerance. 
Grasp the fixed cam (1 1/4) and rotate it to 
the right, increasing the tolerance be- 
tween the gears. Then gently rotate the 
cam counterclockwise to the point 
where the first resistance of the gears 
meshing is felt. Secure the set screws 
(7/2) on the worm gear. Move the posi- 
tioning collar against the worm gear and 
tighten the set screw (7/3). 



1V4 j/t 




COMMENT 

If the tolerance is too tight the machine 
will run slow. If the tolerance is too loose 
the machine will have a knock when zig- 
zagging and/or the needle bar will jump 
swiftly toward the right when on the up- 
stroke. 

After making this adjustment the timing 
of the zigzag movement must be set. 



55 



FOOT CONTROL 

REQUIREMENTS 

The speed should be continuously controllable from a slow speed of 100 ±g° 
rev./min. to full speed. 

The connection contacts to both the wall socket and the terminal board must not 
be damaged or deformed. 

TO CHECK 

Test the foot control on a machine which is known to operate normally. 
If a satisfactory result is not obtained exchange the faulty foot control. 
If the cable or plugs are damaged exchange the cord. 

COMMENT 

The speed controls for models with electronics do not incorporate the standard 
ohms resistor used on earlier models. The new control has a potentiometer which 
is a switching mechanism that operates on low voltage. The actual speed control 
is the printed circuit board. This type of control cannot be used in place of the 
conventional controllers now employing ohms resistors or vice versa. 




57 



TERMINAL BOARD 

REQUIREMENTS 

All connections and cables must be 
securely fixed to their corresponding 
binding post. 

COMMENT 

The terminal board is color coded for 
correct wiring. 

If there is interference in radio or tele- 
vision reception from the machine, 
exchange the interference suppressor 
(condenser). 



condenser 




58 



MOTOR 

COMMENT 

The functioning of the motor can be 
checked without dismounting the 
printed circuit board. First check the 
carbon brushes for wear and to see that 
a carbon is not sticking in the brush 
holder. 

If the motor still does not function, use a 
spare circuit board and connect it to the 
connections on the terminal board. Test 
the machine to see if it functions prop- 
erly. 

If the motor runs normally the fault was 
in the printed circuit board. If it still does 
not function correctly the fault is in the 
motor which must be replaced. 



- 








It— j 










u 


~~1^ 








<s>& 


:. k 




- 






©E- 


T\ 


wn - 






I 

f 


J^S 


5k 


/fjWJI _ 






_J 


TT 


4p^PJ 


L 


> 


— sn 


=h^-Ql 


( — 






■ 











NOTE The procedure to remove the circuit board and for installation of a new 
one are on the following page. 

male and female joint 




59 



PRINTED CIRCUIT BOARD 

DRIVING OF THE MOTOR 

If the machine operates when the motor 
is connected with a spare part circuit 
board but not when the mounted circuit 
board is connected, remove the faulty 
circuit board and send it in for repair. 

COMMENT 

Note that the brush holder and open 
wiring of the motor and the rear of the 
printed circuit are electrified as soon as 
the wall plug is connected. The on/off 
switch does not de-electrify the printed 
circuit. Make it a habit of removing the 
plug from the wall socket as soon as the 
belt guard is removed and only recon- 
nect when it is absolutely necessary. 

REMOVAL 

Loosen the 5 screws in the board which 
hold red, black, white, yellow and blue 
wires. The lighting cable and condenser 
(0.1 /*F) should remain connected. Re- 
move the 2 screws (the cross-grooved 
screws) which hold the printed circuit 
boa-d and separate the conductor joint 
at the motor. Remove the covering from 
the wires and push the wires through the 
hole in the terminal board. 




60 



PRINTED CIRCUIT BOARD continued 



ASSEMBLY 



Assembly should be carried out in a cor- 
responding way, i.e., affix the covering of 
the wires and push the 5 wires back 
through the hole in the terminal board. 
Note that the wires must be connected 
to their respective colors. Replace the 
printed circuit board and press the con- 
ductor joint in, making sure each corre- 
sponding colored wire matches. 





61 



THE LOWEST SPEED OF THE MOTOR 

REQUIREMENTS 

The machine should manage a lowest speed of 1 00 ± g° rev./min. 

DETERMINATION 

Remove the wall plug. Set the thread take-up lever at the lowest position and remove the 
handwheel. Remove the belt guard. Set the stop-right pushbutton at the neutral position. 
Connect the machine but remember that .the brush holder and open wires of the motor 
and the rear of the printed circuit are electrified and unprotected, even if the main switch 
is off. Turn on the main switch. Start the machine and depress the foot control so that the 
machine runs at the lowest possible speed. 

Count the number of revolutions during 15 seconds (i.e., 25-30 revolutions). A piece of 
paper placed under the presser foot will indicate the number of needle holes. 

ADJUSTMENT 



The number of revolutions can be 
adjusted by means of the lower poten- 
tiometer (P1). Turn the potentiometer 
counterclockwise for a higher speed, 
clockwise for a lower speed. 

COMMENT 

There are magnetic bars (reed switches) 
on the upper part of the printed circuit 
board which sense the position of the 
handwheel. These must not come into 
contact with metal objects. For this 
reason always set the thread take-up 
lever at the lowest possible position 
when removing or replacing the hand- 
wheel, so that the indication plate of the 
handwheel cannot come into contact 
with the reed switches. 




pi 



62 



TAKE HOME TURNING SPEED 

EXPLANATION 

The homing speed is a measurement of the capacity of the electronics to turn the upper 
main shaft after release of the foot control. It should be sufficient to drive the machine to 
the selected stop-right position. 

DETERMINATION 



Set the stop-right pushbutton to the up or down position. Handwheel must be 
dismounted. Start the machine and depress the foot control so that the machine runs at 
the lowest possible speed. 

Release the foot control. The speed must not increase during the first second but a slight 
decrease is acceptable. 



ADJUSTMENT 

The homing speed is set by means of the 
upper potentiometer (P2). A higher speed 
is obtained by turning the potentiometer 
counterclockwise, a lower speed by turn- 
ing it clockwise. 

COMMENT 

The homing speed should be sufficient 
to drive the machine to the selected 
stop-right position. However, if the speed 
is too high, the machine will make extra 
stitches after release of the foot control. 




63 



SETTING THE UPPER STOP-RIGHT 
POSITION OF THE NEEDLE 

REQUIREMENTS 

When the needle stops at the upper stop-right position the distance between the stitch 
plate and the needle tip should be between 14 and 9 mm. (The sole of standard presser 
foot is 14 mm.) 

ADJUSTMENT 

With the thread take-up lever in its lowest position mount the handwheel with the 
indication plate at the top. Engage the stop-right to the up position. Press the foot control 
and release it. Measure the distance between the stitch plate and needle tip as per 
requirement. If correction is required, the upper stop-right position is set by moving the 
plate in the handwheel to the right to raise the needle, to the left to lower the needle. 

COMMENT 

This adjustment ensures that all the thread has cleared the shuttle system and the 
sewing project can easily be removed. 




64 



INTRODUCTION FOR 
SERVICE ADJUSTMENTS 

This Technical Service Manual contains 
ail the adjustment procedures that 
should be checked when doing a 
complete service on a Viking Husqvarna 
sewing machine. 

These procedures should be followed in 
sequence, because certain adjustments 
will influence others. 

There are some requirements that do not 
appear on earlier model machines. If this 
is so, skip the requirement and move on 
to the next procedure. 

Before beginning the following checks, 
install a new size 90 needle. It is impor- 
tant the machine is adjusted as close to 
the requirements as possible. Use the 
gauges where applicable and use good 
tools on the machines. 



65 



THE RAISE OF THE CAM FOLLOWER 

REQUIREMENTS 



Set the pattern selector knob for zigzag 
and the stitch length knob and width 
knob at 4. Turn the handwheel until the 
cam follower (11/37) reaches the highest 
point on a cam lobe. Then turn the stitch 
width knob to zero. In this position the 
cam follower should be raised 0.5 - 1.0 
mm over the cam lobe. 

ADJUSTMENT 

Turn the eccentric screw (11/64) until the 
required gap is obtained. The adjustment 
screw is friction loaded and may be 
turned in either direction. 

COMMENT 

This adjustment ensures that the stitch 
width cam follower will not be riding a 
cam lobe when the machine is set for 
straight sewing. Thus, no zigzag on a 
straight stitch. 

NOTE On older style machines with- 
out the adjustment screw 
(11/64), taking the zigzag out of 
the straight stitch is discussed 
later in this manual. 



11/37 11/64 




11/37 



66 



ALIGNMENT OF THE 

STITCH WIDTH CAM FOLLOWER 

REQUIREMENT 



The cam follower (11/37) should meet the 
programmer or fixed cam in the middle 
of a cam disc. 

ADJUSTMENT 

If adjustment is necessary, lower the 
lamp assembly, and insert a long screw- 
driver through the oval-shaped opening 
in the thread tension mounting plate. 
Loosen the set screw (11/45). Manually 
position the cam follower in or out until 
ttie correct alignment is obtained. 
Secure the set screw. 

COMMENT 

If this adjustment is off then the cam 
follower will ride two lobes. 

NOTE On the following page is the pro- 
cedure for making this adjust- 
ment on models 4310, 4010. 




67 



CENTERING THE 

STITCH WIDTH CAM FOLLOWER 

MODELS 4310, 4010. 

REQUIREMENTS 

The cam follower must ride on the 
middle of a cam disc. 

ADJUSTMENT 

Set the stitch selector at the zigzag 
symbol and the stitch width knob at posi- 
tion 4. Turn the handwheel until the cam 
follower rides a lobe on the zigzag cam. 
Loosen screw 1 and adjust the cam 
guide. Tighten the set screw. 




2 1 



NOTE On the following page is the procedure for making this adjustment on 
models 51, 21. 



68 



CENTERING THE 

STITCH WIDTH CAM FOLLOWER 

MODELS 51, 21 

REQUIREMENTS 

The stitch width cam follower must ride 
on the middle of a cam disc. 

ADJUSTMENT 

Set the pattern selector to 5 and the 
stitch width to 4. Turn the handwheel 
until the cam follower comes to the top 
of a cam lobe. Loosen set screw (1), then 
cam guide (2) and the cam can be adjust- 
ed to the correct position. Tighten the 
set screw. 




69 



RETRACTION OF THE ZIGZAG CAM FOLLOWER 

REQUIREMENTS 



Set the stitch selector at zigzag, the 
stitch length and width knobs at 4. Turn 
the handwheel until the cam follower 
(11/37) reaches a cam lobe. Place the 
indicator point of the stitch selector in 
front of the index point. In this position 
the cam follower should lift 0.3-0.4 mm 
from the cam lobe. 



tl/37 



ADJUSTMENT 

Turn the eccentric screw (11/47) until the 
required lift is reached. The screw is 
friction loaded. It can be turned in either 
direction, but at no time should it be 
turned more than 180 degrees left or 
right. 

COMMENT 

If the zigzag cam follower does not raise 
the required amount it could come in 
contact with a cam lobe causing the pro- 
grammer to disengage. If there is too 
much clearance there will be a bind in 
the draw rod to the needie bar frame. 




0,3-0,4 



70 



TIMING THE ZIGZAG MOVEMENT 

REQUIREMENTS 

The side movement of the needle when sewing zigzag should be completed before the tip 
of the needle reaches the level of the stitch plate. Rotate the handwheel and set the 
needle bar in its lowest possible position. The tip of the cam follower (11/37) should be 
directly centered on the cam lobe. 



ADJUSTMENT 

Rotate the handwheel and loosen the set 
screws (7/2) on the worm gear. Set the 
pattern selector to the white dot taking 
pressure off the cam. Rotate the hand- 
wheel and place the needle bar in its 
lowest position. Rotate the worm gear on 
the main shaft, revolving the fixed cam 
so the tip of the cam follower is centered 
on a cam lobe (11/37). Ensure the worm 
gear is firmly against the positioning 
collar on the main shaft. Secure the first 
set screw. 

If the set screw is not available, grasp 
the programmer and load it by firmly 
turning clockwise. At the same time 
rotate the handwheel forward in the run- 
ning direction until a set screw is avail- 
able. Recheck the requirement. 

COMMENT 

If this adjustment is not correct, crooked 
feeding and needle breakage will occur. 



11/4 




11/37 




71 



NEEDLE BAR FRAME STOP 

REQUIREMENTS 

The needle bar frame stop must not prevent the needle from reaching the full zigzag, but 
should stop the needle from going outside the needle hole In the stitch plate. 

CHECK I 

Set the pattern selector for zigzag and the stitch width knob at 4. Turn the handwheel 
until the needle tip is level with the stitch plate and in the left-hand position. Test by 
pushing gently against the needle bar that there is a little play between the frame and the 
stop. It should not be possible to push it so far that the needle tip goes outside the needle 
hole in the stitch plate. But it is acceptable if the side of the needle rubs the stitch plate. 

CHECK II 

Remove any programmer in the machine and set all control dials to the blue symbol. 
Rotate the handwheel and check that the tip of the needle just enters the stitch plate slot 
on the right. It is acceptable if the side of the needle touches the stitch plate. 

ADJUSTMENT 



The position of the stop is adjustable 
with the screw (6/29). 

COMMENT 

Check II prevents needle breakage if the 
customer fails to install a programmer 
and has the control dials set to the blue 
symbol. 




NOTE To make this adjustment on 6010 and earlier models see the next page. 



72 



NEEDLE BAR FRAME STOP 

MODELS 6010 AND EARLIER 

REQUIREMENTS 

The needle bar frame stop (1) must not prevent the needle from reaching the full zigzag, 
but should stop the needle from going outside the needle hole in the stitch plate. 

CHECK 

Set the machine for maximum zigzag. Turn the handwheel until the needle tip is level with 
the stitch plate and in the left hand position. Test by pushing gently against the needle 
bar that there is a little play between the frame and needle bar stop (1). It should not be 
possible to push it so far that the needle tip goes outside the needle plate hole. But it is 
acceptable if the side of the needle rubs the stitch plate. 

ADJUSTMENT 

The position of 
the stop is 
adjusted with the 
screw (2). 




Stop plate Screw Needle bar frame 



73 



CENTERING THE MAXIMUM ZIGZAG WIDTH 

REQUIREMENTS 



The zigzag position of the needle should 
be symmetrically positioned in the 
needle hole. 



sns?' 



ADJUSTMENT 

Set the stitch width knob at 4. Turn the 
handwheel until the needle is well into 
the stitch plate on the right side. Observe 
the distance between the edge of the 
stitch plate slot and the side of the 
needle. Rotate the handwheel and put 
the needle down on the left side. The dis- 
tance should be the same as on the right 
side. The position of the needle can be 
adjusted two ways: 

(a) Remove the stitch pattern 
scale in the direction of the arrows. 
Rotate the handwheel and put the needle 
down on the side that has the largest 
clearance. Place the Adam key into the 
set screw (4/7) and lift up to loosen the 
screw. Remove the tool. Place the tip of 
the screwdriver into the slotted eccentric 
(4/8). By turning the eccentric left or 
right, move the needle bar over one-half 
the required distance observed. Rotate 
the handwheel and check for equal clear- 
ance. 



Rfnsj 



l 



k 



IE39 





488-01 



74 



CENTER THE MAXIMUM ZIGZAG WIDTH 

CONTINUED 
COMMENT 



If the eccentric screw (4/8) is ^shifted 
axially, this will affect the needle posi- 
tion front to rear. If the required needle 
position cannot be obtained, turn the 
screw (4/8) to a middle position and 
tighten the set screw (4/7) and adjust the 
position as follows: 

(b) Put the box spanner 41 11 
907-01 on the nut (8/30) and loosen the 
screw (8/29) in the center of the nut. Turn 
the box spanner until the required posi- 
tion is obtained. Tighten the screw (8/29). 

NOTE To make this adjustment on the 
30 series turn to the following 
page. 




8/30 
r-8/29 



75 



CENTERING THE MAXIMUM ZIGZAG WIDTH 

30 SERIES 
REQUIREMENTS 

The zigzag position of the needle should be symmetrically positioned in the needle hole. 
ADJUSTMENT 

Set the stitch width knob at 4. Turn the handwheel until the needle is well into the stitch 



plate on the right side. Observe the 
plate slot and the side of the needle. 
Rotate the handwheel and put the needle 
down on the left side. The distance 
should be the same as on the right side. 
To make a correction loosen the set 
screw (1). The shaft on the grooved wheel 
(2) is eccentric and when turned the posi- 
tion of the needle is altered. Turn the 
grooved wheel until the requirement is 
met. Tighten the set screw (1). 

NOTE I If the grooved wheel is moved 
axially (in the direction of the 
arrows) the needle position 
front to rear will be affected. 

NOTE II To make this adjustment on 
model 6020 and earlier see 
the next page. 



distance between the edge of the s itch 




76 



NOTE Before tightening screw (1) 
make sure the eccentric (2) is 
flush to the drawrod. 



23 



a 



F 



CENTERING THE MAXIMUM ZIGZAG WIDTH 

20 SERIES AND EARLIER MODELS 
REQUIREMENTS 



The zigzag position of the needle should 
be symmetrically positioned in the 
needle hole. 

ADJUSTMENT 

Set the pattern selector at the zigzag 
symbol and the stitch width knob at 4. 
Turn the handwheel until the needle is 
well into the stitch plate on the right 
side. Observe the distance between the 
edge of the stitch plate slot and the side 
of the needle. Rotate the handwheel and 
put the needle down on the left side. The 
distance should be the same as on the 
right side. To make a correction, loosen 
screw (1). Adjust the position of the 
needle by means of eccentric (2) until the 
needle movement (zigzag) is centered in 
the stitch plate. Tighten screw 1. 



$ 




J-. -L. 



Fig. 6 




77 



NEEDLE POSITION FRONT TO REAR 

REQUIREMENTS 




t 




The needle must be centered front to 
rear in relation to the needle hole of the 
stitch plate. 

ADJUSTMENT 

Set the stitch width knob at 0. Turn the 
handwheel until the needle is in its 
lowest position. Remove the stitch pat- 
tern scale. Use the Adam key 41 15 
844-01 and insert into the stop screw 
(4/7). Lift up to loosen. Now the shaft (8/4) 
which supports the needle bar frame can 
be shifted back and forth (axially) until 
the required needle position is obtained. 
Tighten the stop screw (4/7). 

COMMENT E 

The shaft (8/4) is eccentric and if turned 
will affect the zigzag position in the 
needle plate. 

COMMENT II 

The distance between the center of the 
needle and the flat part of the needle 
base varies with the thickness of the 
needle. In order that needle (size 120) can 
move freely from the front edge of the 
needle hole, set the needle bar in such a 
way that needle (size 90) is in the middle 
of the needle hole. Needle (size 80) will 
then be slightly behind the center of the 
needle hole. Always set this adjustment 
looking directly from the end of the 
machine. 



NOTE To make this adjustment on 30 series machines see the following page. 



1 



~T 




41 15 486-01 




78 



NEEDLE POSITION FRONT TO REAR 

30 SERIES 

REQUIREMENTS 

The needle must be centered front to 
rear in relation to the needle hole of the 
stitch plate. 

ADJUSTMENT 



Set the stitch width knob at 0. Turn the 
handwheel until the needle is in its 
lowest position. Loosen set screw (1). 
Now the grooved eccentric wheel (2) can 
be pivoted in the direction of the arrows. 
Center the needle in the stitch plate hole. 
Tighten the set screw. 

NOTE I 

If the grooved eccentric wheel is turned 
the zigzag position in the stitch plate will 
be affected. 

NOTE II 




Use a size 90 needle when setting this 
adjustment. 

NOTE III 

To make this adjustment on the 20 series 
or earlier models refer to the next page. 



79 



NEEDLE POSITION FRONT TO REAR 

20 SERIES AND EARLIER MODELS 

REQUIREMENT 

The needle must be centered front to 
rear in relation to the needle hole of the 
stitch plate. 

ADJUSTMENT 

Set the stitch width control at so the 
machine is in center needle position. 
Turn the handwheel until the needle is in 
its lowest position. Loosen screw (1) and 
move the needle bar frame in the direc- 
tion of the arrow until the needle is cen- 
tered in the stitch plate hole. 

NOTE Use a size 90 needle when set- 
ting this adjustment. 




Fig. 1 




— Ed£l> 



80 



CHECKING FOR ZIGZAG 
ON A STRAIGHT STITCH 



NOTE 

This is applicable to all machines that 
have automatic buttonholes but do not 
have the adjustment screw (11/64) on the 
stitch width cam follower. 

REQUIREMENTS 

When the machine is set for straight 
sewing the stitch width cam follower 
should not ride a cam lobe. 

ADJUSTMENT 



11/37 11/64 




V_f\ 



0.5-1,0 



Set all controls for straight sewing. Run 
the machine at a moderate speed and 
check that the stitch width cam follower 
has no movement. If movement is detect- 
ed, turn the vertical adjustment screw (1) 
clockwise in one-quarter increments 
until the movement ceases. 

COMMENT 

If the adjustment screw (1) is turned too 
much clockwise the cutting space of the 
buttonhole will be too wide. If it is turned 
too much counterclockwise the cutting 
space will be nonexistent. 




81 



LEFT NEEDLE POSITION 

REQUIREMENTS 

The left-hand needle position shall be in accordance with the left-hand zigzag position. 

CHECK 

Lower the feed teeth. Set the stitch selector on the zigzag symbol and the stitch width 
knob at 4. Place a piece of masking tape under the presser foot. Carefully pierce the tape 
with the needle in the left-hand position; turn the handwheel backwards so the needle is 
above the tape. Set the stitch selector at the symbol for left-hand position, then set the 
stitch width dial at 0. Guide the needle towards the tape. The needle must go into the 
same hole as before. 

ADJUSTMENT 



Turn the upper eccentric screw (11/41) to 
meet the requirements above. 

COMMENT 

When turning the eccentric screw (11/41) 
always turn it clockwise. Always set this 
adjustment when the needle is moving 
towards the end of the open arm. 

NOTE It is very important that the zig- 
zag is centered in the stitch 
plate before making this adjust- 
ment. 



11/41 




82 



CENTER NEEDLE POSITION 

REQUIREMENT 

The needle should be in the center, of the zigzag. 
CHECK 

Lower the feed teeth. Set the stitch selector at the zigzag symbol and the stitch width 
knob at 4. Place a piece of masking tape under the presser foot and pierce it on both the 
right and left sides of the zigzag. Now set the stitch width knob at 0. Turn the handwheel 
until the needle pierces the tape. This hole should be centered between the two zigzag 
holes. 

ADJUSTMENT 

Turn the lower eccentric screw (11/41) 
clockwise until the needle reaches the 
above requirement. 

COMMENT 




This adjustment eccentric, like that of 
the left-hand eccentric, must always be 
turned clockwise, and must always be 
set with the needle traveling toward the 
end of the open arm. 

NOTE I It is very important that the 
zigzag is centered in the 
stitch plate before making 
this adjustment. 

NOTE II For making this adjustment 
on machines without auto- 
matic units, i.e., models 21, 
19, 51, 49, 1020, 1030, etc., 
refer to the following page. 



■t" 



U- 



£1^3 



__._ i 




11/41 



83 



CENTER NEEDLE POSITION 

MODELS WITHOUT AUTOMATIC UNITS 
REQUIREMENT 

The needle should be in the center of the stitch plate hole. 

CHECK ADJUSTMENT 



Set the knob for the needle 
position on the middle 
symbol. (For machines 
with pattern selectors set 
on 5.) Turn the stitch width 
knob to 0. Turn the hand- 
wheel until the needle tip is 
below the stitch plate. The 
needle should be in the 
center of the stitch plate. 




-G^> 



Loosen screw (1) and press 
the guide (2) in the direc- 
tion of the arrow so that 
the needle comes between 
the center and left needle 
positions. This will release 
pressure on the guide (2). 
Now by adjusting the guide 
bring the needle to its 
center needle position. 
Tighten screw (1). 




Cl. 49 



84 



NEEDLE BAR HEIGHT 

REQUIREMENTS 

When the tip of the hook passes the center of the needle, the gap between the tip and the 
upper edge of the needle eye should be 1.5 mm. Since this is a difficult measurement to 
determine, another method is suggested. Place the shuttle in the driver. Put the needle in 
its lowest position. By looking straight on, determine that one-half of the needle eye is 
visible above the outer guard ring of the shuttle (hook). 

ADJUSTMENT 



Loosen screw (8/34) and move the needle 
bar up or down to the requirement. 
Moderately tighten the set screw. 

COMMENT I 

When measuring the position of the 
needle eye be sure to hold the hook 
downward and counterclockwise. This is 
the position it is in when the machine is 
running. 



— /-8/34 




COMMENT II 



The needle bar is tubular, so when tight- 
ening the set screw (8/34), just secure it 
moderately, so not to deform the needle 
bar. 



Hool 



1/2 of eye is visible 
above ring 




85 



NEEDLE BAR ALIGNMENT 



REQUIREMENT 



The needle must be parallel to the stitch plate 
hole and shuttle (hook). 

ADJUSTMENT 

Install a 4.0/90 double needle. Rotate the 
handwheel and put the needles in the their 
lowest position. Look directly from the end of 
the open arm to see if the needles are parallel 
to the stitch plate. To adjust loosen set screw 
(8/34) and without moving the needle bar up or 
down twist it until they are parallel. Tighten 
set screw. 



VJronc 




8/34 



PATH OF HOOK 



COMMENT 

Remember that the needle bar is tubular. If the set screw is tightened too much, the 
needle bar may become deformed and the machine will run in a bind. 



86 



NEEDLE TO HOOK CLEARANCE 

REQUIREMENTS 



Remove the shuttle cover. 

Set the stitch selector for straight 

sewing. 

Insert the needle gauge No. 41 15 800-02 

into the needle bar. Lay the machine on 

its back. 

When the tip of the hook is in front of the 

center of the needle press the hook 

against the driver. The gap between the 

needle and the hook should not exceed 

the maximum 0.4 mm. 

COMMENTS 




*±* 



o.t 



K 



ra 



Setting Needle View B. Scale 2! 
Distance 



, £ 



^=- 



The hook must have some axial movement so the thread loop is able to go between the 
hook and drive. This makes contact between the needle and hook possible. This contact 
can be heard if the machine is running without thread. The hook is designed with a 
needle support which meets the contact. This contact damages neither the hook or the 
needle as long as the needle system 705 H is used. This system of needles has a scarf on 
the back side. 

ADJUSTMENT 



Settings according to requirements. 
Turn the handwheel until the needle is in 
its highest position. The slot in the driver 
is now in the middle, underneath the feed 
dog. Undo the three screws which hold 
the hook cover — remove the hook cover 
and the hook. Then undo the three 
screws (9/11) in the driver (9/10), and 
remove it. The position of the driver is 




87 



NEEDLE TO HOOK CLEARANCE 

continued 

adjusted by removing or adding one or several shims. When putting the driver back on the 
machine, note the position of the slot and install in the same position as when removed. 

NOTE I The shuttle cover clearance must be checked after this adjustment. 

NOTE II if sufficient adjustment is not possible by removing all the shims, see the 
comment and procedures below. 

NOTE III For making this adjustment on models 49, 51, 71, etc., see the next 2 pages. 



COMMENT 

If all shims have been removed and there 
is still no clearance between the needle 
and hook, first make sure the needle (90) 
is centered front to back in the needle 
plate. If set correct and still no clear- 
ance, follow procedures for moving 
shuttle gear and bushing. 

PROCEDURES 

Remove the driver (9/10) and the dust 
guard (9/9). Loosen the two screws (9/19) 
in the cog wheel. Move the cog wheel to 
the right 1 mm and moderately secure 
one of the screws. Loosen the screw 
(9/37) for the bushing (9/4) on the shuttle 
shaft. The screw can be reached through 
the hole in the casting through the base 
plate. With this screw loose, shift the 
gear and bushing to gain the required 
clearance. Tighten screw (9/37). 

NOTE I Move the gear and bushing 
only as much as needed. If 
they are moved too much the 
machine could run noisy. 

NOTE II Set the shuttle gear toler- 
ance as we described earlier 
in this manual. 



9/T9 



9/22 9/24 




9/23 9/27,28 9/29 




9/37 



88 



NEEDLE TO HOOK CLEARANCE 

MO DELS: 49,51 ,71 ,6320,631 0,431 0,1 31 0,331 0,3320,etc. 
REQUIREMENTS 



Remove the shuttle cover. Set the stitch 
selector for straight sewing. Insert the 
setting gauge No. 41 15 800-02 into the 
needle bar. Lay the machine on its back. 
When the tip of the hook is in front of the 
center of the gauge as in Fig. 25, press 
the hook against the driver. The gap be- 
tween the needle and the hook should be 
as small as possible. 
Max. 0.4mm. See Fig. 26. 

ADJUSTMENT 

Loosen screw (1). Remove or insert 
shims to meet requirement. 




0. 1 (.003<l^L_ 




Fig. 26 



Fig. 25 




89 



SHUTTLE TIMING 

REQUIREMENTS 

Set the stitch selector for straight 
sewing. As the needle is moving upwards 
the tip of the hook should pass the 
center of the needle when the needle is 
2.5 mm above its lower turning position 
(the distance for forming the loop). 

ADJUSTMENT 

Remove the shuttle cover. Remove the 
inspection plate cover under the base 
plate. There are three screws on the 
pulley, one untreated (9/27) and two 
black ones (9/28). Remove the untreated 
screw and one of the black screws and 
change their places, still leaving them 
loose. Then loosen the other black screw 
enough so that the lower shaft still turns 
when the handwheel is rotated. 
Turn the handwheel until the needle is in 
it lowest position. Place the setting 
gauge 41 11 752 on the needle bar. Push 
the gauge up until the spring-loaded stud 
just touches the needle bar frame and 
tighten the screw. Turn the handwheel in 
the same direction as the machine runs 
until the spring-loaded stud rests against 
its stop in the gauge according to the 
right-hand figure. The needle has now 
moved up 2.5 mm from 




NOTE 

The tip of the hook 
at the centre of 
the needle 




9/27 9/28 9/29 



90 



continued 

the turning position (the distance for forming the loop). Hold the handwheel fast and turn 
the hook and the driver so that the tip of the hook comes in front of the center of the 
needle. Secure one of the black screws. Turn the handwheel in the opposite direction 
until the needle returns to its lower turning position. Hold the hook back with one finger, 
so that it is pushed downwards and backwards, and turn the handwheel in the same 
direction as the machine runs. When the stud on the setting gauge is once again resting 
against its stop, the tip of the hook should be in the center of the needle. Tighten the 
remaining black screw, then the silver untreated screw. 

NOTE I 

Before tightening the first black screw press the chain belt pulley to the left removing any 
possible play in the lower main shaft. 

NOTE II 

To make this adjustment on earlier models see the next page. 



91 



SHUTTLE TIMING 

FLAT-BED ALL MODELS 

Set the machines, classes 51 and 
49 for straight stitching in the 
middle needle position. Loosen 
the three screws on the pulley 1 
Fig. 22. Turn the handwheel until 
the needle reaches its lowest 
turning position. Place the clamp 
41 11 752 on the needle bar as 
shown in Fig. 20. Push the clamp 
upwards until the spring loaded 
stud touches the needle bar 
frame. Secure the clamp on the 
needle bar. Turn the handwheel 
until the spring-loaded stud rests 
against its stop in the gauge as 
shown in Fig. 21. By turning the 
handwheel in the same direction 
the machine runs the needle has 
raised 2.5 mm from its original 
position. During this movement 
the thread loop to be caught by 
the hook is formed. There is a 
certain play between the hook 
and the driver and at this setting it 
is necessary to press the hook 
inwards/downwards toward the 
driver so that it rests against the 




Fig. 22 



Clamp 



Lowest turning 
position 




Fig. 20 



Fig. 21 



92 



continued 

lower edge of the driver. At the same time, turn the hook to the left until the catch on the 

back of the hook rests against the left side of the slot in the driver. 

Turn the hook and driver until the point of the hook is in line with the center of the needle. 

See Fig. 21. 

Tighten one of the black screws 1 Fig. 22 on the lower pulley. Remove the clamp. 

Re-check the setting. The remaining untightened screws, the black one and the silver one 

should change places, then tighten them. The silver screw is a head screw with a cone 

point, which makes a cavity (mark) in the shaft. If the two screws do not change places 

there is always the risk that the point will slip back to its old position. Old machines are 

not supplied with such a cone point screw. 

COMMENT: 

After making this adjustment the feed height eccentric will require adjustment. See page 
107. 



93 



SHUTTLE COVER CLEARANCE 

REQUIREMENTS 

The gap between the shuttle cover and the driver should be such that when the hook Is 
exchanged for the hook clearance gauge 41 1 1 649 or 41 1 1 635, the gauge should have no 
play but can be turned. 

ADJUSTMENT 



Dismantle the shuttle cover (9/15) and exchange the hook for gauge 41 11 649 or 41 11 

635. Re-assemble the shuttle cover. Loosen the three screws (9/14) which fasten the 

posts to the free arm. Check that the posts move easily in their holes in the free arm. The 

clearance between the hook cover and the driver is adjusted by displacing the holders in 

the appropriate direction. This is done in two stages. 

Begin with the posts (1 and 3). These are adjusted simultaneously by carefully pushing 

the shoulders screws (9/16) with the fingertips until they rest against the hook cover in 

the cover holes. The two posts should then be fastened to the arm by means of the 

screws (9/14). Then adjust the height of the post (2). To avoid too much clearance 

(at point No. 4) in the hook, light pressure 

should be applied at this point on the 

hook cover instead of on the post (2). 

This ensures that the post (2) is lifted up 

somewhat. The post should then be 

fastened by means of the screw (9/14). 

Thereafter, check that the correct 

clearance is attained. There should be 

slight resistance when turning the 

gauge. 

NOTE 

To make this adjustment on older style 
machines, see following page. 





9/15 



W "^x 



9/1 ^ 




94 



0.4 (.0157") 



SHUTTLE COVER CLEARANCE 

ALL FLAT-BED MODELS 

Loosen half a turn the two screws 4, Fig. 28 which secure the retainer 2. Screw off the 
shuttle cover and replace the hook with adjusting gauge 41 11 649. See that the two lips 
on the gauge are horizontal in the shuttle cover, so that the cover is guided up sideways 
in line with the hook. When tightening up the shuttle cover again, take care that the re- 
tainer is taken up carefully. 
Adjust the hook clearance 
by carefully pressing at the 
same time on the screws 1 
and 3, and pressing 
uniformly so that screw 3 
is not pressed deeper in- 
wards than 1. Retighten 
the screws 4, Fig. 28. 
Before fitting in the hook 
again make a final check to 
ensure that the correct 
clearance has been obtain- 
ed. With light pressure on 
the adjusting gauge, feel 
that it is neither pinched 
nor has any clearance. 
When turned slowly the ad- 
justing gauge should give a 
light resistance. 




\ 




} 



41 11 649 




95 



FEED TEETH 
ALIGNMENT 

REQUIREMENT 



The feed teeth should be aligned parallel 
to the slots of the stitch plate. 

ADJUSTMENT 

Turn the handwheel until the feed teeth 
are at their highest position. Remove the 
stitch plate and loosen the 2 mounting 
screws (10/2). Remount the stitch plate. 
Manually shift the feed teeth until they 
are aligned parallel to the stitch plate. 
Carefully remove the stitch plate so the 
feed teeth do not shift. Hold the feed 
teeth and securely tighten the mounting 
screws. 





96 



LEFT TO RIGHT CENTERING OF THE FEED TEETH 

REQUIREMENT 

The feed teeth should move freely in 
the stitch plate grooves. 



ADJUSTMENT 

Loosen the screw (10/14) on the feed 
dog carrier. Shift the carrier until the 
feed teeth are centered in the stitch 
plate slots. Tighten screw (10/14). 

NOTE 

To set this adjustment on earlier 
models, see following page. 



10/5 




10/14 



97 



LEFT TO RIGHT CENTERING OF THE FEED TEETH 

MODELS: 6310, 4310, 3310, 1310, ALL FLATBED MODELS 
REQUIREMENT 

The feed teeth should move freely in the stitch plate grooves. 

ADJUSTMENT 

Loosen screws (1) and (2). Move the feed bar and the pivots (3) until the feed teeth move 
freely in the stitch plate grooves. Tighten screws (1) and (2). 

NOTE 

Check that the feed bar moves easily and is without play in the bearings against the 
pivots (3). 




1 3 



2 3 



98 



CENTERING THE FEED TEETH FRONT TO REAR 

REQUIREMENTS 

The feed teeth must not strike against 
the stitch plate when the machine is set 
at the maximum stitch length, neither at 
forward nor reverse feeding. 



ADJUSTMENT 

Turn the handwheel until the needle bar 
is in its highest position. Set the stitch 
length knob at zero. Undo screw (10/5) 
and looking from the end of the open arm 
position the feed teeth in the center of 
the stitch plate grooves. Tighten screw 
(10/5). Check according to above. 

NOTE 

To make this adjustment on older style 
machines see the following page. 




10/14 



99 



CENTERING THE FEED TEETH FRONT TO REAR 

MODELS: 6310, 6320, 4310 3310 1310 49, 51, 71, ALL FLAT-BED MODELS 
REQUIREMENTS 



The feed teeth must not strike against 
the stitch plate when the machine is set 
at the maximum stitch length, neither at 
forward nor reverse feeding. 

ADJUSTMENT 

Set the stitch length knob at position 4, 
back off screw (1). Move the feed dog car- 
rier to the position that the feed teeth 
move freely in the stitch plate when sew- 
ing forwards and backwards. Tighten 
screw (1). 





100 



LEVEL OF THE STITCH PLATE 



REQUIREMENT 



The right and left rows of the feed 
teeth should be of equal height 
above the stitch plate. 

CHECK 

Install the arm sleeve and stitch 
plate. Place the feed dog height 
gauge over the feed teeth. 
Looking straight through determine 
if the requirement is met. 

ADJUSTMENT 

Locate the small adjustment screw 
on the arm sleeve, as illustrated. 
Turn the adjustment screw to raise 
or lower the stitch plate until there 
is equal clearance of the feed teeth 
rows. 



WRONG 



adjustment screw 




RIGHT 



adjustment screw 




101 



FEED DOG HEIGHT 

REQUIREMENT 

The height of the feed dog over the stitch plate should be checked with the gauge 41 11 
735, which should be placed under the presser foot. The stitch length knob should be set 
at zero. Turn the handwheel until the feed dog reaches its highest position. The feed dog 
teeth should be level with the gauge, but should not lift it. 

ADJUSTMENT 



Through the inspection plate open- 
ing in the base plate loosen screw 
(10/24) and place the feed teeth 
against the gauge. Tighten screw 
(10/24). 

COMMENT 

With the gauge 41 1 1 735, a feed dog 
height of 1 mm is achieved. 

NOTE 

For older style machines, i.e., 4310, 
3301, 1310, 71, 51, 49 etc. see follow- 
ing page. 




| ' " ' ] 41 11 735-01 

I n «i nit J 



10/24 




102 



FEED DOG HEIGHT 



ALL FLAT-BED MODELS 



REQUIREMENT 

The height of the feed dog over the 
stitch plate should be checked with 
the gauge 41 11 735, which should 
be placed under the presser foot. 
The stitch length knob should be set 
at four. Turn the handwheel until the 
feed dog reaches its highest posi- 
tion the feed dog teeth should be 
level with the gauge, but should not 
lift it. 



Gauge 




ADJUSTMENT 



Loosen screw 
(1) and raise or 
lower the feed 
teeth so that 
the require- 
ment is met. 
Tighten screw 

(1). 

Check that the 

gauge does 

not move 

when the 

handwheel is 

turned. 




103 



THE FEED DOG DROP 

REQUIREMENT 

Set the machine at maximum stitch length and drop the feed dogs. Rotate the handwheel 
forward. Bring the feed teeth to the front forward feeding position. The front edge of the 
feed teeth should clear the shuttle cover. 

ADJUSTMENT 

Support the machine level on its back. Through the inspection plate opening in the base 
plate is the adjustment screw (10/28). Turn the adjustment screw clockwise to raise 

the support level, and 
counterclockwise to lower it. 10/28 

COMMENT 



The adjustment screw is set in a 
clear nylon mounting block. This 
mounting block is loose and 
under no circumstances should it 
be tightened. 




104 



FEED TIMING 

CHECK 



Set the stitch length dial to 2.5 Rotate the handwheel and bring the 
needle bar to its highest point. Press the reverse button in then release, 
in then release, etc. in a fast motion. Notice the feed teeth are traveling 
front to rear. Continue engaging the reverse button and slowly rotate the 
handwheel forward until the feed teeth stop moving. The tip of the needle 
should measure 14.0 mm above the level of the stitch plate. 

COMMENT 

Use the feed dog height gauge to make the measurement which is 14 mm 
wide. Position the gauge level on the stitch plate surface (the feed teeth 
must be lowered). The needle tip should come right to the edge of the 
gauge. 

ADJUSTMENT 

Loosen screw (7/8) on the feed eccentric. Rotate the handwheel to raise 
or lower the needle until the needle tip comes level with the gauge. 
Tighten screw (7/8). 



NOTE I The feed eccentric is spring-loaded, so when screw (7/8) is 
loose it will want to rotate backward. Use a screwdriver or a 
finger to prevent this. If it does happen and the position is lost 
turn the feed eccentric collar until the screw (7/8) is facing out 
and if thread take-up lever is in an up position tighten screw 
(7/8) and start the adjustment again. 



NOTE II For older style machines see the following pages. 




105 



FEED TIMING 

MODELS: 6310, 4310, 3310, 1310, ALL FLATBED MODELS 

This adjustment is done in the same way as the preceding page with 
these exceptions: 

1. When the feed teeth stop moving, the tip of the needle should 
measure 12 to 14mm above the level of the stitch plate. 

2. On the feed eccentric there are two and sometimes three ad- 
justment screws. In the case where there are more than one 
color screw, always loosen just the silver screw(s). 



NOTE I This adjustment ensures the feed teeth are not moving the 
fabric while the needle is either entering or leaving the fabric. 

NOTE II For models 6310, 4310, 3310, 1310, the height eccentric must 
also be set. See the following page. 




106 



SETTING THE HEIGHT ECCENTRIC 

MODELS: 4310, 3310, 1310, FLAT-BED ALL MODELS 
CHECK 

Set the stitch length knob at 4. Rotate the handwheel until the thread 
take-up lever is in its lowest position, making sure the feed teeth are mov- 
ing upward. 

At this point, the top of the feed teeth should be level with the stitch 
plate. 

ADJUSTMENT 

Loosen screws (1), and turn the height eccentric until the above position 
is reached. Tighten screws (1). 




107 



ALIGNMENT OF THE REVERSE ARM CAM 
FOLLOWER 



REQUIREMENT 

Install the A programmer, Set the stitch 
selector at the blue symbol. Turn' the 
handwheel until the cam follower (11/22) 
reaches the highest point of a cam lobe. 
The cam follower should now meet the 
programmer in the middle of a cam disc. 

ADJUSTMENT 

Loosen the screw (11/21). Move the cam 
follower in or out to meet the require- 
ment. 
Tighten screw (11/21). 




108 



THE RETRACTION OF THE REVERSE ARM 
CAM FOLLOWER 

REQUIREMENTS 

Install the A programmer and set all control dials to the blue symbol. 
Turn the handwheel until the cam follower (1 1/22) is on top of a cam lobe. 
Turn the pattern selector dial and set it half way between the yellow and 
blue symbol. The tip of the cam follower should retract 0.2 to 0.3 mm from 
the cam lobe. 

ADJUSTMENT 



Loosen the locking nut (2). Turn the inner adjustment screw (3) 
counterclockwise to increase the clear- 
ance, clockwise to decrease. Secure the 
locking nut (2). On the older version 
reverse arms loosen the locking screw 
(1 1/25). Turn the adjustment screw (11/23) 
left or right to obtain the desired clear- 
ance. Secure the locking screw (11/25). 




New version 



11/22 



0.2-0.3 




11 23 11/25 



Older version 



109 



HEIGHT AND ALIGNMENT 
OF THE PRESSER BAR 

REQUIREMENT 

The presser bar should be set in such a way that when raised it reaches 6 
to 7 mm. When it is lowered the presser bar must be parallel to the stitch 
plate. 

ADJUSTMENT 

Snap on the regular zigzag presser foot. Place the presser bar gauge 
directly under the foot. The gauge should fit under the foot with a slight 
resistance. Check to see that the edge of the gauge is parallel to the 
seam allowance mark on the stitch plate. To make an adjustment loosen 
the set screw (6/39). Twist the gauge so that its edge is parallel to the 
seam allowance mark. From the top of the machine, press down firmly on 
the presser bar and then secure the set screw (6/39). 



NOTE 

For earlier model machines, the presser 
bar height should be set at 6 mm. On 
later series machines having the new 
style needle clamp, the presser bar 
height should be set at 7 mm. 6/39 

COMMENT 

On the underside of the button-hole foot 
is a guide which steers the fabric. If the 
presser bar is not aligned properly, the 
columns of the buttonhole will be af- 
fected. 



341 



/ 




4113 161-01 



110 



UPPER THREAD TENSION RELEASE 



REQUIREMENT 



When the presser bar lifter is down, the 
lever for the thread tension release (1) 
should not touch the release arm (2). 

CHECK 

Raise the presser bar lifter and remove 
the thread tension knob. Check to see 
that the tension discs separate enough 
for two threads to pass through on either 
side. Lower the presser bar and check 
that the thread tension release arm has 
play. 

ADJUSTMENT 

The lever for the thread tension release 
can be adjusted by eccentric screw (3). 
Turn it clockwise to decrease the separa- 
tion of the discs, and counterclockwise 
to increase the separation. 

NOTE 

To make this adjustment on older series 
machines see the following two pages. 




111 



UPPER THREAD TENSION RELEASE 



MODELS: 6020, 6010, 3310, etc. 

REQUIREMENT 

When the presser bar lifter is up, the 
thread tension discs should have 
enough clearance to accept 2 sew- 
ing threads on each side. 

ADJUSTMENT 

With the face plate door closed, turn 
the adjustment eccentric (1) until 
the correct clearance between the 
discs is obtained. 

NOTE 

To make this adjustment on older 
series machines, see the following 
page. 




112 



UPPER THREAD TENSION RELEASE 



MODELS: 2000, 21, 19, 8, 71, 51, 49, t etc. 

REQUIREMENT 

When the presser bar lifter is at its 
lowest position the distance bet- 
ween the thread tension release 
lever and the thread tension release 
pin should be 1.5 mm. 

ADJUSTMENT 

The distance can be adjusted by 
turning the eccentric screw (1). 

COMMENT 

When the presser bar lifter is at its 
highest position the function of the 
thread tension release lever is to 
force the thread tension release pin 
into the thread tension assembly. 
The result of this is that the 
pressure on the thread tension discs 
is released. 




113 



SETTING THE UPPER THREAD TENSION 

COMMENT 

To set tensions use a medium weight cotton fabric such as muslin. The 
quality and fiber content of the thread has a definite effect on the tension 
balance. Use a high quality sewing thread. Install a size 80 needle and 
thread the sewing machine in the normal way. 
Explained are two ways of setting the upper thread tension. 

ADJUSTMENT I 

Remove the thread tension knob (1). Lower the presser bar lifter. Turn the 
thread tension dial until there is some separation of the tension discs. 
Now turn the dial the other way until the discs just come together. Install 
the thread tension knob lining up the zero with the indication mark. Turn 
the tension dial to the red dot. The top tension should now be close to the 
required tension. 

ADJUSTMENT II 

Remove the thread tension knob (1). Lower the prsser bar. By looking 
straight on notice that the needle is centered in relation to the presser 
foot ankle. The thread tension is correct when the thread is pulled to the 
rear right corner of the stitch plate and the needle deflects parallel with 
the right edge of the ankle. Turn the tension dial to meet this require- 
ment. Install the thread tension dial at the red dot. Pull the thread to 
deflect the needle and hold this position. Take hold of the tension dial 
and rapidly turn it to the buttonhole symbol. The needle should move as 
the thread tension is relaxed. 





114 



SETTING THE THREAD TENSION OF THE 
BOBBIN CASE 

REQUIREMENT 

The thread tension spring of the bobbin case should give the resistance 
of 20-24 grams when pulling the thread slowly. 

ADJUSTMENT 

Check that the tension spring is not damaged and remove any loose 
pieces of thread or lint which may be under it. This can be tested by using 
something weighing approximately 22 grams. It is possible to use a 
stitch programmer. Fasten the thread in the programmer and hold the 
bobbin case in a way that the thread comes out vertically in the direction 
of the projection on the bobbin case. If the thread tension spring is set 
correctly, the weight of the programmer will slowly withdraw the thread 
from the bobbin. Adjust by turning screw (9/36). 



COMMENT 

The best way to test that the ten- 
sions are set correctly is to set the 
Stitch width knob at 4 and stitch 
length at 2V2. Proper thread tension 
is set when the lower thread is pull- 
ed directly to the corners of the 
zigzag on the underside of the 
fabric. 

NOTE 

The type of presser foot as well as 
the fabric is an important factor in 
obtaining the proper results. 





115 



THREAD FEEDING (CHECK) SPRING 

REQUIREMENT 

The casing (1) should be set so that the thread feeding spring has finish- 
ed its movement when the eye of the needle reaches the fabric. 

ADJUSTMENT 

Have machine threaded in the normal way. Set the stitch length to 4. 
Take 4 or 5 stitches and test requirement. To adjust turn the adjustment 
casing clockwise to increase the spring's travel and counterclockwise to 
decrease. Retest until requirement is met. 

COMMENT 



When the thread feeding spring 
stops moving there should be a loop 
of thread formed in front of the 
needle. The thread loop should be 
fairly straight, but relaxed. 

NOTE 

To do this adjustment on older style 
machines see the following three 
pages. 




116 



THREAD FEEDING (CHECK) SPRING 

MODELS: 6020, 6010, etc. 

REQUIREMENT 

Set the machine at stitch length 2.5. Have machine threaded in the nor- 
mal way. Sew 4 - 5 stitches. Then turn the handwheel forward in the 
running direction until the needle eye just reaches the fabric. At this 
point the thread feeding spring should have completed its movement. 

ADJUSTMENT 

Raise or lower the adjustment lug (2) until the requirement is met. 
COMMENT 



When the thread feeding spring 
stops moving there should be a 
loop of thread formed in front of 
the needle. The thread loop 
should be fairly straight, but 
relaxed. 

NOTE 

To do this adjustment on older 
style machines see the follow 
ing two pages. 




117 



THREAD FEEDING SPRING 

MODELS: 49, 51, 71, etc. 
REQUIREMENT 

The same as the preceding page. 

ADJUSTMENT 

To adjust move the regulating lever (3). If the lever is moved to the left the 
travel of the spring will increase and vice versa. 

COMMENT 

When the thread feeding spring stops moving there should be a loop of 
thread formed in front of the needle. The thread loop should be fairly 
straight, but relaxed. 

NOTE 

To do this adjustment on machines without the regulating lever (3), see 
the following page. 




3*0 




118 



THREAD FEEDING SPRING 

MODELS: 21, 51, 71, 7 
REQUIREMENT 

Same as the preceding two pages. 

ADJUSTMENT 

Loosen screw (1) and insert a 
screwdriver into the end of the ten- 
sion stud. Then turn the entire ten- 
sion assembly with a screwdriver to 
the position where the requirement 
is met. 
Tighten screw (1). 

COMMENT 

When the thread feeding spring 
stops moving there should be a loop 
of thread formed in front of the 
needle. The thread loop should be 
fairly straight, but relaxed. 




119 



BUTTONHOLE COLUMN EQUALIZATION 

REQUIREMENT 

When the indication marks on the reverse button and 
reverse button cap are lined up the columns of the but- 
tonhole should be equal. 







ADJUSTMENT 



Sew steps 1 and 3 of the buttonhole. Check the button- 
hole columns as per requirement. If an adjustment is 
needed, first turn the outer knob of the reverse button to 
its correct position; 3:00 o'clock on the latest series of 
machines and 12:00 for older series machines. Remove 
the reverse button cap. Turn the inner adjustment nut 
counterclockwise to increase the density of the column 
on the right side, and clockwise to decrease the density. 

NOTE 

Another way to remember which way to turn the nut — 
always turn the nut towards the tight side. 





120 




BUTTONHOLE CUTTING SPACE 

REQUIREMENT 

The proper cutting space is equal to two 
sewing threads laying side by side 
between the buttonhole columns. 

ADJUSTMENT 



The screw (12/1) is the adjusting screw. 
To increasae the cutting space turn the 
screw clockwise. To decrease the cut- 
ting space turn the screw counter- 
clockwise. 

COMMENT 

The adjustment of the cutting space 
affects the width of the zigzag. When the 
cutting space is increased, the zigzag 
width is reduced and vice versa. Recheck 
the machine for zigzag on a straight 
stitch. 

NOTE 

To do this adjustment on machines 
without an automatic buttonhole 
mechanism, see the following page. 




121 



BUTTONHOLE CUTTING SPACE 

MODELS: 6310, 3310, 1310, 1000 and 3000 SERIES MACHINES 

REQUIREMENT 

The proper cutting space is equal to two sewing threads laying side by 
side between the buttonhole columns. 

NOTE 



On these model machines this adjustment directly affects the width of 
the zigzag. 

ADJUSTMENT 

Sew a test buttonhole. If adjustment is necessary loosen screw (1). It can 
be reached through the inspection plate opening in the base plate. The 
cutting space is increased by moving the link (2) downwards. The cutting 
space is reduced by moving the link upwards. 



COMMENTS 

Check the zigzag width in the stitch 
plate. Check that the seam former is not 
worn. And check that the cam follower 
retracts over the cam lobe when the 
stitch width knob is turned from 4 to 0. 





122 



REVERSE FEED EQUALIZATION 

REQUIREMENT 

Install the A programmer, and turn all control settings to the yellow area. 
Make sure the stitch length is centered in the yellow area. Sew a seam 
6-8 inches long. Remove the fabric and evaluate the elastic straight 
stitch for equal forward and reverse 
feeding. When this is correct, there will 
be almost perfect holes at the beginning 
and end of the stitch. 

ADJUSTMENT 

To make a corrective adjustment on the new version reverse arm, turn the 
adjustment screw (1) clockwise to increase the pattern density, 
counterclockwise to elongate the pattern. On machines with the older 
version reverse arm, first loosen the locking screw (2), then turn the ec- 
centric (3) as described before. 



Older version 



New version 




123 



THE WORM GEAR 

THE RESETTING OF THE FEEDING MOVEMENT 
REQUIREMENTS 

Install the A Programmer. Set all the controls to the blue symbol and sew 
a seam 8 to 10 inches long to evaluate the configuration of the overlock 
pattern. The seam on the left side should be perfectly straight. 

COMMENT I 

A direct relationship exists between the movement of the zigzag and the 
feeding of the automatic reversing patterns. 

ADJUSTMENT 



If there is a fault in the pattern, turn the 
pattern selector to the white dot and set 
the width at O. Loosen one set screw 
(7/2) on the worm gear. Rotate the hand- 
wheel and loosen the other set screw. 
Hold the worm gear stationary and 
against the positioning collar. Rotate the 
handwheel backward and observe one 
quarter inch movement of the needle bar. 
Secure the set screw and retest the pat- 
tern. The seam on the left side should be 
perfectly straight. 

COMMENT II 

This setting of the worm gear gives a 
more functional setting than that of tim- 
ing the zigzag movement. It is not neces- 
sary for the zigzag movement to be sym- 
metrical. 







124 



CORRECT AND INCORRECT BOBBIN 
WINDING 



T 



ii n 




Fig. 1 illustrates how a correctly wound bobbin should look. If the bobbin 
winds unevenly, adjustment can be made in the following way. First 
remove the covering until the screw which holds the thread guide in 
place is accessible. (Note that the screw underneath, which connects the 
belt guard to the rear cover, should remain untouched). If the bobin wind- 
ing looks like example 2, turn the screw clockwise until winding is even. 
If it looks like example 3, check that the bobbin is properly pressed onto 
the shaft. If this is in order, turn the screw counterclockwise until wind- 
ing is even. 



125 



THREAD TAKE-UP LEVER 
SLIDE BEARING REMOVAL 



COMMENT 



The replacement of the slide bearing is 
the same for most models. The same 
basic principles of removal apply to all 
models. 

STEPS FOR REMOVAL 

1. Rotate the handwheel and place the 
thread take-up lever in its highest 
position. 

2. Turn the pressure control dial to the 
darning symbol. 

3. Remove the four screws (1, 3, 4 and 5) 
for the thread tension mounting plate. 
NOTE A 

Before removing the mounting plate, 
observe the presser bar control lever 
(2), notice how the yoke fits above the 
nylon washer and the spring on the 
presser bar. 
NOTEB 

On machines with fold-down handles, 
after removing the thread tension 
mounting plate, reinstall the handle 
mounting screw (1). 

4. Remove the two mounting screws (6) 
and dismount the thread take-up 
lever. 




127 



I 
38 39 



47___ 

48 -W 

49 



i 



34 
35 

36 
37 



Fig. 1 



Fir. 2 




34 

35- 



36- 



_/ 



■^£=» J 



^>- 



39- 



37 

38 

40 



128 



SLIDE REMOVAL continued 

5. Remove the presser foot holder mounting screw Fig. 1 (48) and remove the 
presser foot ankle Fig. 1 (49). 

6. Loosen the screw Fig. 1 (39) in the presser bar guide. 

NOTE 

Before removing the presser bar observe the position of the presser bar 

components Fig. 1 (34, 35, 38, 36). 

7. Slide the presser bar up, and at the same time, remove the small lower spring 
Fig. 1 (36), presser bar guide Fig. 1 (38), presser bar tension spring Fig. 1 (35), 
and the nylon washer Fig. 1 (34). 

8. Remove the needle bar frame return spring Fig. 2 (28). Use a spring tool, reach 
in and disconnect the spring from the edge of the casting. 

9. Separate the draw rod at the connection to the needle bar frame by removing 
the locking screw Fig. 2 (29) and adjusting nut Fig. 2 (30). Notice the washer 
Fig. 2 (31) is between the draw rod and needle bar frame. 

10. Remove any needle from the machine. 

11. Rotate the handwheel and position the needle bar down about 1 /z its throw. 
Pivot the needle bar frame outward. Then remove the mounting screw* Fig. 2 
(13) and separate the connecting rod Fig. 2,(14) from the crank stud Fig. 2 (17). 
*NOTE 

On all models, the mounting screw Fig. 2 (13) has left-hand threads. Turn the 
screw clockwise to remove. 



129 



Fig. 2 



2 3 4 



\M--pi -C=D 



1 — ©> 



34- 

35- 



38- 



^ 

tl 



X 






iO 37 

38 



29- 



-(g£@^=© 40 



31 41 



Fig. 3 




z^» 




130 



SLIDE REMOVAL continued 

12. Looking from the rear of the machine rotate the handwheel until the large set 
screw Fig. 2 (23) is visible. Loosen the screw 2V2 turns. With the tip of the 
screwdriver on the screw head, tap inward, driving the set screw flush against 
the needle bar crank collar. 

13. From the head of the machine take hold of the thread take-up lever mounting 
frame Fig. 2 (9) and remove from the machine. In some cases the crank collar 
Fig. 2 (22) will come out too. Prevent this by placing a finger on it so it remains 
in the machine. 

14. Remove the crank stud Fig. 2 (17) and slide Fig. 2 (18). 

COMMENTS FOR INSTALLING THE NEW SLIDE TO CRANK STUD 

When installing the new take-up slide bearing to the crank stud, the rounded, 
tapered area of the slide goes on the crank stud first. Place the small tension 
spring Fig. 2 (19) and the retention washer Fig. 2 (20) on the crank stud shaft. A 
true-arc clip Fig. 2 (21) is used to secure the slide to the crank stud. Compress 
the spring with the retention washer. Fit the clip to the groove on the crank 
stud shaft. 

STEPS FOR INSTALLATION 

NOTE The crank stud with slide must be installed with the take-up lever 
frame. The take-up lever frame slide shaft Fig. 2 (8), as it fits to the 
bearing, must be installed so that it is at the top of the machine. 
Position the crank stud Fig. 2 (17) so that the flat is toward the top of 
the machine. Make sure the flat on the lock bolt Fig. 2(11) which is in 
the crank collar Fig. 2 (22) is facing down. 
1. Place the take-up lever frame on the mounting shaft and fit the crank stud to 
the crank collar Fig. 2 (22). 



131 



SLIDE BEARING INSTALLATION continued 

NOTE 

Do not exert pressure or attempt to force the assembly. The assembly will fit 
smoothly together. 

2. Prior to securing the mounting screw Fig. 2 (23) on the crank collar, install the 
thread take-up lever Fig. 2 (6). 

3. Press inward on the needle bar crank collar Fig. 2 (22) and secure the large 
mounting screw Fig. 2 (23). 

4. Remove the thread take-up lever. 

5. Connect the needle bar connecting rod to the crank stud, mount the screw 
Fig. 2 (13) and tighten. 

6. Connect the draw rod to the needle bar frame. First put the washer Fig. 2 (31) 
between the draw rod and needle bar frame, then install the locking screw Fig. 
2 (29) and adjusting nut Fig. 2 (30). Tighten screw. 

7. Install the needle bar frame return spring Fig. 2 (28). 

8. Install the presser bar. Start the bar through the casting and put the washer 
and tension spring on first. Then the presser bar guide and last the small lower 
spring. Lightly secure the screw Fig. 1 (39) on the presser bar guide. 

9. Install the thread take-up lever. 

10. Put the thread take-up lever in its highest position. Install the face plate 
making sure the yoke on the presser bar control lever is above the nylon 
washer and spring on the presser bar. 

ADJUSTMENTS TO CHECK 

A. Centering the zigzag width in the needle plate. 

B. Height and alignment of the presser bar. 



132 



EXCHANGING THE FIXED CAM 
AND WORM WHEEL 

COMMENT 

Changing the fixed cam and worm wheel is nearly the same for all models. There 
are a couple of differences which are explained in detail. Whenever a difference is 
explained it is absolutely necessary to follow the instructions to prevent any 
binding of the machine after installation. 

Set the pattern selector to the center needle position and the zigzag width at 0. 
Support the machine in a level position on its face so the back of the machine is 
facing you as in Fig. 4. 

STEPS FOR REMOVAL 

1 . Remove the mounting screw (1) on the fixed cam guide. 

NOTE The screw is spring loaded. The connecting arm for the reverse feed 
cam follower retraction will keep the screw from coming completely 
out of the machine. Observe for reinstallation purposes how the fixed 
cam guide (4) fits into the groove in the fixed cam. 

2. Grasp the fixed cam (2) and lift it out of the machine. 

3. Remove the screw (3) in the center of the worm wheel. Notice the position of the 
steel washer (which is tapered to receive the screw head) and the nylon washer.- 
Leave these both on the screw (3). 

NOTE On the model 2000 and the 10 series there is a collar and nylon friction 

washer which must be removed. 
NOTE The 20 series machines employ a C-clip on the worm wheel shaft that 

must be taken away. 

4. Remove the worm wheel. 



133 




134 



FIXED CAM AND WORM WHEEL INSTALLATION 

COMMENT 

When replacing either the fixed cam or worm wheel always replace them with the 
matched set part number 41 15 984-60. 

STEPS FOR INSTALLATION 

1. Mount the new worm wheel on the pattern selector shaft and engage the worm 
wheel to the worm gear on the main shaft. 

2. Firmly secure the mounting screw (3). 

NOTE Models 2000 and the 10 series have a collar to secure the worm wheel. 
Turn the pattern selector to left needle position. Mount the nylon friction 
washer and collar to allow 0.5 mm to 1.0 mm end play of the worm wheel. 

COMMENT 

The fixed cam must not bind against the collar. Install additional nylon friction 

washer(s) as required to maintain the 0.5 mm to 1.0 mm clearance. 

NOTE 20 series machines employ a C-clip to mount the worm wheel. Check that 
there is 0.5 mm clearance. 

NOTE Starting with the 30 series machines the worm wheel mounting is con- 
trolled by the pattern selector mounting screw. The 0.5 mm must be 
checked after installation to the machine. 

NOTE The 40 series machines incorporated a one-piece nylon worm wheel. This 
worm wheel is longer so the friction washer is not necessary. 

COMMENT 

If the later style fixed cam and metal worm wheel is to replace a one-piece unit, 
i.e., 40 series worm wheel, a friction washer will be necessary to maintain the 
required 0.5 mm end play. 
Order number 41 10 592-01 nylon friction washer. 



135 



WORM WHEEL INSTALLATION continued 

3. Fit the fixed cam to the worm wheel aligning the groove in the fixed cam to the 
key on the worm wheel. With the tip of a screwdriver, make sure the cam guide 
is in the slot of the cam. 

COMMENT 

To secure the mounting screw (1) to the cam guide (4) without stripping it, read 
step 4 below carefully. 

4. Set the machine upright. Press inward on the cam guide mounting screw (1) 
with a screwdriver. At the same time, rotate the pattern selector and draw the 
cam all the way inside the machine. Continue to press in on the screw. Grasp 
the fixed cam and carefully move in or out to position the cam guide to the 
screw. Rotate the screw counter-clockwise until the threads engage. Secure 
the screw. 

ADJUSTMENTS TO CHECK 

A. Timing of the zigzag. 

B. Raise of the cam follower. 

C. Zigzag cam follower retraction and alignment. 

D. Reverse feed cam follower alignment. 



136 



PATTERN MECHANISM, STITCH LENGTH UNIT 
AND STITCH WIDTH UNIT REMOVAL 

COMMENT I 

To exchange the zigzag unit it's easier to remove the pattern selector and stitch 
length device and remove the unit from the rear of the sewing machine. The steps 
for removal are explained in a sequence that would be used if the stitch width 
unit were being replaced. Therefore, if the stitch length unit was the only unit to be 
replaced, it is necessary to remove only the parts directly involved for removing 
the pattern selector and stitch length device. 

COMMENT II 

It is recommended that all the parts be laid out in the order and position in which 
they are removed. 

STEPS FOR REMOVAL 

1. Lower the lamp assembly and remove the light bulb. 

2. Remove the mounting screw for the lamp bracket. Observe the position of the 
lamp bracket and how it's mounted. 

3. Remove the center cover and mounting screw for the pattern selector. Lift off 
the dial, coil tension spring and color scale. 

4. Pull out the zigzag dial and engage the unit to position two of the buttonhole 
sequence. Remove the center cover and mounting screw and lift away the dial, 
spring and scale. 

5. From the back of the machine, remove the star washer Fig. 5 (1) with the tip of a 
screwdriver. Observe how the connecting link Fig. 5 (2) of the reverse arm 
engages the stitch length device before dismounting the arm. 

6. Remove the C-clip Fig. 5 (3) that joins the connecting link from the zigzag 
mechanism to the draw rod. Press inward on the connecting link to separate its 
connection with the draw rod. 



137 




138 



PATTERN MECHANISM REMOVAL continued 

7. Disconnect the spring Fig. 5 (4) attached to the connecting link. The spring is 
fixed to the zigzag mechanism and may be released. 

8. Press down on the arm that the connecting link is fixed to. Lift up, separating 
the link from the arm and remove from the machine. 

9. The needle position support arm from the buttonhole cam must then be 
separated from the curved arm of the pattern selector. With the tip of a 
screwdriver spring load the curved arm Fig. 5 (5) of the pattern selector 
upward. Applying pressure, shift the support arm for the buttonholer directly 
to the right. At this point, the support arm for the buttonholer must be lifted 
out and moved to the left across the face of its connection point with the 
curved arm of the pattern selector. It is convenient to gently wedge the arm 
against the stitch regulator fork. This will hold it in a position out of the way 
during removal of the pattern selector. 

10. Remove the mounting screw Fig. 5 (6) in the center of the pattern selector. 

11. Remove the pattern selector by grasping the pattern selector frame and 
moving it side to side while pulling it out. Once it's out of the machine make 
the following observations. 

OBSERVATION I 

How the lamp wire comes up across the front of the pattern selector 'rame, 

and then to the rear, over the top of the lamp bracket. 

OBSERVATION II 

The spring is attached differently to the front of the pattern selector frame, 

depending on the model. 

12. Separate the spring from the pattern selector and lift the unit out. 



139 




Fig. 7 




140 




141 



STITCH LENGTH UNIT REMOVAL continued 

13. Remove the plate Fig. 6 (1) on the rear of the machine. Observe that the spring 
is attached to the stitch regulator fork. 

14. Remove the needle position support arm Fig. 7 (1) for the buttonhole cam. 
Observe its connection to the buttonhole mechanism. 

15. Loosen the set screws Fig. 8 (1) on the chain belt sprocket one-quarter turn 
and shift the sprocket to the right. 

16. Rotate the handwheel so that the set screw on the feed eccentric is available. 
Loosen the set screw Fig. 8 (2) and shift the feed eccentric collar to the right 
separating the slide block on the stitch regulator fork from the stitch length 
guide. Lightly tighten the set screw. 

17. Through the inspection plate of the sewing machine, loosen the set screw Fig. 
9(1). 

18. Separate the stitch regulator fork bearing Fig. 9 (2) from the rocker bar. 
NOTE 

On models 6440, 60 series, and 70 series the fork may be hard to separate 
from the rocker bar because the lower chain belt sprocket interferes. It may be 
necessary to spring load the rocker bar to gain the additional clearance. From 
the rear of the free arm, place a screwdriver against the casting and spring 
load the arm collar on the rocker bar to the left and hold. Now separate the 
stitch regulator fork bearing from the rocker bar. 
NOTE 

For all earlier models a different method is used to separate the stitch regu- 
lator fork from the rocker bar. Remove the two C-clips Fig. 10 (1) and slide the 
pin to the left. Separate the stitch regulator fork bearing from the rocker bar. 



142 




143 



STITCH LENGTH AND WIDTH UNIT REMOVAL 

CONTINUED 

19. Remove the stitch regulator fork by pulling it down through the opening of the 
bottom plate to one-half its length. Turn the fork clockwise so it is sideways in 
the machine and remove it from the bottom. 

20. Remove the stitch length knob and scale by pulling it off. 
COMMENT 

On the latest series of machines there is a tapered nylon ring used to center 
the stitch length mechanism in the casting. From inside the machine, with the 
tip of a screwdriver, apply pressure around the outside edge of the nylon ring 
until it is separated. 

21. Remove the large mounting screw Fig. 11 (1). 
COMMENT 

On models with an electronic circuit board the board must be removed from 

end of the machine. 

22. Grasp the mounting collar directly underneath the handwheel. Pull and rotate 

to remove the collar. 

NOTE 

Observe the hole in the collar. When reinstalling this is placed in alignment 

with the mounting screw. 

23. Remove the stitch length mechanism from the machine. 

24. Remove the mounting screw for the zigzag mechanism. 

NOTE 

On the latest series machines with the dual idler wheel on the V-belt, there is a 
spring from the dual idler to the stitch width unit. It must be unhooked. 

25. Remove the mechanism by lifting it directly out the rear of the machine. 



144 




145 



INSTALLATION OF STITCH WIDTH, 

STITCH LENGTH AND PATTERN MECHANISMS 

COMMENT 

Installation of the mechanisms is the opposite of removal. At each stage of instal- 
lation, it is a good idea to ensure that each mechanism performs the proper 
function. 

STEPS FOR INSTALLATION 

NOTE The return spring for the drop feed button is friction mounted to the 
shouldered area on the front of the frame. When installing the button- 
hole mechanism, at all times the spring must remain firmly in position 
on the shouldered area. Also, during installation of the new mechanism, 
ensure that the drop feed return spring fits into the slotted area in the 
drop feed button. 

1. Install the buttonhole mechanism and secure the mounting screw. 

2. Attach the color scale, spring and the control dial. 

3. Engage the mechanism to position 2 of the buttonhole. 
NOTE 

If machine is a late series with the dual idler wheel, the spring from the wheel 
needs to be connected to the stitch width unit. 

4. Install the stitch length mechanism. 

5. Install the mounting collar for the stitch length mechanism. Align the hole in 
the collar to the screw hole in the casting. 

6. Install the tapered nylon ring. 

7. Mount the screw Fig. 11 (1). 

8. Install the stitch length knob and scale. 



146 



continued 

9. Ensure that the friction plate and slide block are on the stitch regulator fork. 
Install the fork through the opening in the base plate. Turn the fork sideways 
so the slide block is facing upwards. Push the fork through the opening over 
the rocker bar bearing and slide it upwards past the stitch width unit. Once 
past the stitch width unit turn the fork counterclockwise until it's in the 
correct position. Push the fork into the feed eccentric cam. Loosen the screw 
Fig. 8 (2) and move the feed eccentric to the left and install the slide block into 
the stitch length guide. Tighten screw Fig. 8 (2). Spring load the rocker shaft 
again and at the'same time turn the handwheel until the regulator fork pin is 
lined up with the bearing. Push the pin inside bearing. Tighten set screw Fig. 9 

(1). 

Check to see that the reverse button can be pushed in and released without 
sticking. If sticking occurs there needs to be more play between the stitch 
regulator fork slide block and the stitch length guide. Loosen screw Fig. 8 (2). 
Move to the required tolerance, tighten screw Fig. 8 (2). 

10. Connect the plate Fig. 6 (1) to the spring from the stitch regulator fork. Secure 
the screw to the plate. 

11. Install the needle support arm Fig. 7 (1) for the buttonhole cam. Gently wedge 
the arm against the stitch regulator fork. 

12. Move the chain belt to the left to its original position and secure the two 
screws Fig. 8 (1). 

13. Connect the lamp wire spring to the pattern selector frame in the same 
manner as it was originally connected. 

14. Make sure the lamp wire comes over the top of the lamp bracket. 



147 



INSTALLATION OF THE PATTERN SELECTOR 

CONTINUED 

15. Install the pattern selector. 

16. Install the mounting screw Fig. 5 (6) and washers. 

17. Make sure the draw rod guide is in the stitch width cam follower. 

18. Connect the needle position support arm to the curved arm of the pattern 
selector Fig. 5 (5). 

19. Install the connecting link Fig. 12 (1) to the lever arm of the stitch width unit. 

20. Connect the spring Fig. 5 (4) to the connecting link. 

21. Connect the draw rod to the link and attach the C-clip Fig. 5 (3). 

22. Install the reverse lever arm and star washer Fig. 5 (1). 

23. Mount the lamp bracket to the lamp socket and secure with screw. Install 
light bulb. 

24. Mount the pattern selector color scale, spring and dial. Secure with screw. Put 
on center cover. 

COMMENT 

After replacing any of the three main mechanisms, it is important to go over the 
service adjustments. 



148 




149 



REDUCTION GEAR REMOVAL 
AND REPLACEMENT 

COMMENT I 

The following procedures for removal and replacement of the reduction gear 
applies to all models beginning with the 20 series. 

COMMENT II 

On later series models with a circuit board, the board must be removed from the 
end of the machine. 



STEPS FOR REMOVAL 

1. Rotate the handwheel and position 
one of the openings on the outside 
edge of the reduction gear pulley, at 
the one o'clock position. Remove the 
mounting screw (14/8). 

2. Rotate the handwheel and reposition 
the opening at the 3 o'clock position. 
Remove the mounting screw (14/9). 

3. Remove the cog belt. 

4. Lift the reduction gear out of the 
machine. 



STEPS FOR REPLACEMENT 

1. Install the reduction gear in the machine. Be sure the V-belt is around the cog 
with belt pulley. 

2. Install the cog belt. 

3. Install the two mounting screws (14/8,9). 
NOTE 

On some models the mounting screw at the 3 o'clock position is the longer one. 

COMMENT 

The cog belt tension must be set. On the latest series of machines the V-belt 
tension will also have to be set. 




150 



BOBBIN CASE REPAIR 

COMMENTS 

When inspecting the bobbin case, make sure that the chrome plating has not 
peeled around the edges. If it has the bobbin case should be exchanged. 
If the customer installed the bobbin case incorrectly, it's possible that the tip of 
the needle could strike the bobbin case on its outside shoulder. This does not 
interfere with the sewing ability of the machine, and is not a reason for replace- 
ment. 

If the thread tension spring, the fixed mounting screw or the tension adjustment 
screw are damaged they should be exchanged. 

When inspecting the bobbin case, take a discarded needle and pass the tip of the 
needle under the thread tension spring to remove thread residue. 
Bobbin case complete, part number 40 11 530-02. 
Individual replacement parts are identified below: 



& 




k 



30 31 32 33 34 35 36 

30 4110 601-01 Shoulder Screw 

31 40 11535-02 Latch 

32 40 11 536-01 Spring 

33 40 11 531-02 Bobbin Case Housing 

34 40 11 781-01 Thread Tension Spring 

35 22 86 200-41 Screw 

36 20 71211-46 Screw 

NOTE 

On some earlier models the bobbin case parts differ with numbers (35) which is 
part number 22 88 125-01 and (36) part number 20 74 260-01. 



151 



BOBBIN CASE REPAIR continued 

Make sure the latch (31) moves freely in its mounting on the shoulder screw. If it 
doesn't a new latch spring (32) should be installed. 

STEPS FOR REPLACEMENT OF THE BOBBIN CASE LATCH SPRING 

COMMENT 

It is necessary when installing a new latch spring to apply a twisting pressure; for 
this reason, the latch spring has additional length. It's convenient to use a locking 
tool to hold the spring, in order to apply the twisting pressure. 

1. Install the spring under the side of the bobbin case through the opening (A). 

2. The tip of the spring passes over the top and tucks under the latch so the tip 
protrudes at position (B). 




152 



6. 
7. 



Twist the holding tool and press the spring over the shoulder area on the 

bobbin case. 

Release the holding tool for the spring and with the tip of a small screwdriver, 

from the top of the bobbin case opening, press the spring securely into the 

shouldered area (C). 

With the edge of a screwdriver push the spring down over the shouldered area 

on the left inner portion of the bobbin case (D). 

Test the latch to ensure that it is spring loaded and functioning smoothly. 

From the outside of the case, clip the spring as close as possible to the edge (E) 

with side cutters. 

NOTE 

It is essential that the spring be cut close to the edge. Any portion of the spring 

that protrudes will interfere with thread escapement. 





153 



NOTES: 




///. "A" 



154 



COMPONENT REPAIR 

PATTERN SELECTOR MODELS 2000 • 6570 

The following procedures described to repair defective pattern selectors apply to 
all models. Design changes to improve the function of the mechanism may vary 
the method of assembly. When necessary, comments and illustrations will explain 
the requirements applicable to specific models. 
It is suggested parts be laid out in the order and position removed. 

TOOL REQUIREMENTS 

Box spanner metric size 5 mm old style 

5.5 mm new style 

Tru-Arc pliers Order 41 11 910 

DISASSEMBLY 

1. Remove connecting link III. A (1). Note the position and the manner the return 
spring is attached; it will differ between models. 

2. Loosen the cam guide screw III A. (2). Caution: The screw is spring loaded. 
Remove the screw and tension spring. Note the small fiber washer and the 
screw. 

3. Remove the fixed cam and worm wheel. 
COMMENT 

On 30 series and later machines the worm wheel position is controlled by the 
pattern selector mounting screw. Models 2000 and 10 series have a separate 
collar. Loosen the two set screws and remove the collar, nylon friction washer, 
and worm wheel. 
The 20 series employ a C-clip on the worm wheel shaft. 



155 




111. "B" 




111. "C" 



156 



DISASSEMBLY continued 

4. Remove the lock nut and the two spring steel washers from the left needle 
position eccentric screw III. B (3). 

COMMENT 

Late style pattern selectors have a friction nut with a nylon insert. Older 
models have two nuts, one tightens to compress the concave spring steel 
washers to obtain a friction load for the adjustment screw. The second nut is 
secured against the first to prevent the assembly from loosening should the 
adjustment be turned counter-clockwise. 

5. Remove the Tru-Arc clip III. B (4), lift off the needle position support frame. 
COMMENT 

On later style units the Tru-Arc clip is located behind the needle position 
support frame and will be removed in step 7. 

6. Remove screw III. C (5) and the mounting guide plate. Lift off the main gear with 
cam guide (6). Remove the middle gear wheel (7). 

7. Remove the shoulder mounting screw III. C (8) and lift away the disengaging 
plate, roller, and retention guide plate (9). 



157 



LINK 




NOTES: 



158 



DISASSEMBLY continued 

8. Remove the Tru-Arc clip III. D (10) and take away the link. 
COMMENT 

On later units the link's position is controlled by the Tru-Arc clip. The link posi- 
tion on earlier selectors is maintained by the mounting of the needle position 
support frame, the Tru-Arc clip was removed in step 4. 

9. Press out the elastic tumbler pin from the main shaft cog gear. Remove the 
starting position cog wheel III. D (11) and the main shaft gear III. D (12). 

The pattern selector frame should be thoroughly cleaned in solvent to remove 
dried grease and pieces of any damaged cog gears. Clean and inspect each gear 
closely for damage. 

COMMENT 

For models 2000 through 30 series it is recommended that all gears be replaced. 
Beginning with 40 series a new method of construction for the gears was intro- 
duced. On the 40 series and later models only the defective gear need be replaced. 

For models 2000 and 10 series machines the main shaft cog gear is grooved for 

installation of a concave spring washer and C-clip to attach the pattern selector 

color scale. 

The starting position cog wheel for these models has only one slot for the intrical 

tab on the color scale which determines the correct position and drives the scale. 

The new style gears may be used; however, a change for the mounting of the 

pattern selector scale and knob is necessary. 

For models 2000 the scale retention coil spring used on later models and the 

zigzag knob for the model 2000 is used in place of the original pattern selector 

knob. 

ORDER SPARE PARTS 

41 10 122 Coil spring 

41 11 223 Knob (remove metal sleeve) 

For the 10 series the color scale, retention spring, and pattern selector knob are 
replaced with the parts used on the 20 series. 

ORDER SPARE PARTS 

41 11 992 Scale 
41 10 122 Spring 
41 11 994 Knob 



159 




TIMING MARKS 



111. "E" 



TIMING MARK 




MIDDLE GEAR WHEEL 



111. M F f 



160 



ASSEMBLY 

Closely examine each gear and identify the timing marks. The marks may be 

stamped or be visible as a mold mark. Check that the main shaft cog gear fits 

smoothly on the starting position cog wheel. 

A small amount of lube (light grease) should be applied to each part when 

assembled. Order number 41 14 464 Molycote. 

At each stage of installation the gears must be positioned with the timing marks 

aligned. Failure to maintain the required positions will result in the pattern 

selector not turning to all color settings. 



161 




///. "G" 




III. "H" 



162 



ASSEMBLY continued 

6. Hold the main gear with the timing mark aligned with the mark on the middle 
gear wheel; fit the fixed cam guide to the staged slotted area of the main gear. 
The cam guide must be positioned with the pin in the slot of the pattern 
selector frame and main gear. 

Install the guide plate III. G (5) and secure the mounting screw. 

COMMENT 

The guide plate must not touch the main gear; hold the plate positioned as 

illustrated. 

7. Fit the needle position support frame to the pattern selector and install the left 
needle position eccentric screw III. H (3). 

COMMENT 

Before securing the lock nut to the setting screw ensure the concave spring 

steel washers are placed (outward) opposing each other. 

On older models tighten one nut till the screw turns with firm resistance; hold 

the nut with a box spanner and tighten the second nut securely against the 

first. Recheck to determine the setting screw has enough resistance to hold 

adjustment. 

8. Install the Tru-Arc clip III. H (4) to the needle position support frame post. Check 
that the support frame pivots freely in its mounting. 

COMMENT 

Late style units have the Tru-Arc clip mounted behind the support frame; do not 
employ this assembly on older units or the alignment of the zigzag cam fol- 
lower to the fixed cam will not be possible. 



163 



CAM GUIDE TIP MUST 
FIT INTO GROO VE OF 
FIXED CAM 




m "i" 




in. "j" 



164 



ASSEMBLY continued 

9. Check that the fixed cam moves freely on the worm wheel. Install the worm 
wheel and fixed cam; be sure the cam guide tip is placed in the groove of the 
fixed cam. 

Install the long coil spring and make sure the fiber spacing washer is in place 
and secure the mounting screw III. I (2). 

CAUTION: Do not crossthread the cam guide; if damaged the cam guide must 
be replaced. 



10. Install the connecting link and return spring III. J (1). 

ASSEMBLY TEST 

With the control knob test the unit for correct assembly. Turn the knob clockwise 
till it stops; this should be left needle position. Rotate the knob counter-clockwise 
and determine the following lock positions. 

1. Center needle position 

2. Three step zigzag 

3. Color symbol Blue 

4. Color symbol Yellow 

5. Color symbol Red/Orange 

6. Color symbol Green/Purple 



165 



ASSEMBLY continued 

11. Models 2000 and 10 series machines have a position collar to secure the 
worm wheel. Turn the selector counter-clockwise to the left needle position. 
Mount the nylon friction washer and collar to allow 0.5 mm end play of the 
worm wheel. 

COMMENT 

The fixed cam must not bind against the collar. Install additional nylon friction 
washers as required and maintain 0.5 mm end play. 

20 series machines employ a C-clip to mount the worm wheel; in this situation the 
0.5 mm end play needs to be checked. 

With the introduction of the 30 series the worm wheel mounting is controlled by 
the pattern selector mounting screw. 

COMMENT 

The required 0.5 mm clearance must be checked after installation to the machine. 

40 series machines incorporated a one-piece nylon worm wheel. The worm wheel 
is longer and the nylon friction washer was omitted from installation. 
When reinstalling the original one-piece nylon worm wheel do not install a friction 
washer or the worm wheel will be jammed. 

If the later style fixed cam and metal worm wheel is to replace a one-piece unit, a 
friction washer will be necessary to maintain the required 0.5 mm end play. Order 
number 41 10 592 Washer. 

Should the pattern selector be damaged beyond repair and a complete new unit 
installed, the following details should be noted. Due to similar design, inter- 
changing mechanisms from model to model is possible. 



166 



Pattern selectors from the 20 series are used for replacement on models 2000 and 

the 10 series. 

Pattern selectors for model 6570 replace previous units on the 30 and 40 series. 

COMMENT 

Pattern selector installation models 2000 and 10 series: The zigzag cam follower 
tip is longer than the tip on the later 20 series. The old follower must be installed 
on the new unit. 

30 and 40 series: The latest style pattern selectors for 6570 are used for replace- 
ment. The zigzag follower (slotted) plate from the old unit must be installed and 
the reverse automatic arem with connecting link. 



167 



REPLACEMENT OF THE BOBBIN SPINDLE 

COMMENT I 

There are two different bobbin spindles. The 40 11 882-01 is the older style with the 
straight cut gears. This is used on the 10 series machines and earlier models. The 
41 13 919 is the newest style with helical cut gears. This bobbin spindle is used in 
reduction gears from the 20 series machines to present. 

COMMENT II 

The description for replacing the bobbin spindle will be for the latest series of 
machines, i.e., the 20 series to present. The same basic procedures are used for 
the earlier machines with a few exceptions which are easily figured out. 

STEPS FOR REMOVAL 

1. Remove the reduction gear. 

2. Remove the two screws (32) and then remove the knob (31). 

3. Loosen the black screw (30) on the pulley (29). Then loosen the silver screw (33) 
on the same pulley. Looking directly at the bobbin spindle, notice there is a V 
notched out of the bobbin spindle. The silver screw has a case hardened point 
that is screwed into the notch. Remove the pulley (29). 

NOTE 

There should be a washer (28) in the pulley. It must be in the pulley for the 

reduction gear to run properly. 

4. Notice how the finger in the gear selector (24) fits into the groove in the hub (27). 
Remove the hub (27). 

5. Slide the bobbin spindle away from the cog wheel with pulley (19). Notice the 
position of the cog wheel with pulley to the bobbin spindle. Also, notice how 
the key in the bobbin spindle fits into a notch in the driver (18) which is in the 
cog wheel (19). 

6. Remove the bobbin spindle. 



168 



« 



j^D-@-asB-@" 





169 



INSTALLATION OF BOBBIN SPINDLE 

STEPS FOR INSTALLATION 

1. Place the frame of the reduction gear in a position so the upper cog wheel (5) is 
facing to the left. Place the cog wheel (19), with the driver (18) facing outward, 
over the bearing in the reduction gear. 

2. Install the bobbin spindle. Make sure the key of the spindle goes into a slot in 
the driver. 

3. Install the hub (27) so that the finger in the gear selector (24) is in the groove of 
the hub. 

4. Install the washer (28) and pulley (29). Turn the pulley until the V notch in the 
bobbin spindle lines up with the silver screw. Make sure the bobbin spindle 
gear is flush with driver (18) of the cog wheel (19). Tighten the silver screw, then 
the black one. 

NOTE 

At this point check to see that there is no bind in the reduction gear. Also check 
to see that there is no end play in the bobbin spindle. If either one occurs, 
loosen the silver screw and make the correction. 

5. Install the knob (31) and tighten the 2 screws (32). 



170 



WIRING DIAGRAM 

FLATBEDS CLASSES 49E, 51 , 51 A, 51 E, 71 , 71 E 

MODELS 1310, 3310, 4310, 6310, 6320 

1. INTERFERENCE SUPPRESSORS (40 16 403) 

Connect one lead, terminal point A, one lead terminal point B. Install second 
suppressor leads to terminal point F and terminal point E. 

2. CONDENSER (40 16 524) 

Connect one condenser lead to terminal point C, one lead, terminal point D. 

3. DISCHARGE RESISTOR (40 16 392) 

Connect one resistor lead, terminal point B, one lead, terminal point E. 

4. LAMP 

Connect one lead, terminal point B, one lead, terminal point E. 

5. MOTOR 

Connect one lead, terminal point E, one lead, terminal point D. 

6. POWER SUPPLY CORD 

Connect one lead, terminal point A, one lead, terminal point F. 



DISCHARGE 
RESISTOR 




SUPPRESSOR 



171 



WIRING DIAGRAM 

EARLY MODELS CL 19 - CL 20 

1 . POWER CROSSOVER LEAD 

Install an insulated lead between terminal point B and terminal point H 

NOTE 

Route lead under switch. 

2. LAMP 

Route lamp wires through opening J, connect one lead, terminal point A, one 
lead, terminal point G. 

3. MOTOR 

Connect one lead, terminal point C, one lead, terminal point F. 

4. POWER SUPPLY CORD 

Connect one lead, terminal point D, one lead, terminal point E. 

NOTE 

Secure cord restraint clamp; insure fiber insulation plate is installed or 

damage to the power supply cord will result. 




172 



WIRING DIAGRAM 



CLASSES 8, 19S, 19A, 21, 21 A 

1. LAMP 

Route lamp wires through opening in motor mounting bracket; connect one 
lead, terminal point E, on lead, terminal point F. 



2. MOTOR (4-wire) 

The motor has four leads; two leads have ID bands, yellow and blue. Connect 
yellow band lead, terminal point E, blue band lead, terminal point D. Connect 
one brown lead, terminal point C, one brown lead, terminal point B. 



3. POWER SUPPLY CORD 

Connect one lead, terminal point A, one lead, terminal point B. 

4. MOTOR (Late style 2-wire interchange) 

Connect one lead, terminal point E, one lead, terminal point C. 

NOTE 

All other connections remain the same. 




I 

CONNECTING STRIP 



173 



WIRING DIAGRAM 

CLASSES 19E, 21 E, 2000 

MODELS 0210, 1010, 3010, 4010, 5010, 5210, 6010 

1. DISCHARGE RESISTOR (40 16 500) 

Connect one resistor lead, terminal point G, one lead, terminal point F. 

2. CONNECTING STRIPS (40 16 511) 

Install one connect strip between terminal points B and E, one strip between 
terminal points C and D. 

3. LAMP 

Route lamp wires over top of terminal board. Connect one lead, terminal point 
B, one lead, terminal point C. 

4. MOTOR 

The motor has four leads; two leads have ID bands, yellow and blue. Connect 

yellow band lead, terminal point G, blue band lead, terminal point F. Connect 

one black lead, terminal point B, one black lead, terminal point C. 

NOTE 

Route motor wires through opening A. 

5. POWER SUPPLY CORD 

Connect one lead, terminal point E, one lead, terminal point D. 



DISCHARGE RESISTOR 
I 

t A 

I 




COMPLETE MOTOR 
EXCHANGE 

Four-wire motors are no 
longer available; late style 
two-lead motors interchange. 

Install components and 
rewire terminal board accord- 
ing to instructions for wiring 
diagram models 6020 and 
6430. 



CONNECTING 
STRIPS 



174 



WIRING DIAGRAM 

MODELS 1020, 3020, 3220, 4020, 5220, 6020 

1030, 3230, 4030, 5230, 5430, 5530, 6030, 6430 

1. DISCHARGE RESISTOR (40 16 500) 

Connect one resistor lead, terminal point G, one lead, terminal point F. 

2. CONDENSER (41 14 804) (not shown) 

Connect one lead, terminal point G, one lead, terminal point F. 

3. INTERFERENCE SUPPRESSORS (40 16 514) 

Connect one lead, terminal point E, terminal point B. Install second sup- 
pressor leads to terminal point D, and terminal point C. 

4. LAMP 

Route lamp wires over top of terminal board. Connect one lead, terminal point 
B, one lead, terminal point C. 

5. MOTOR 

Connect one lead, terminal point G, one lead terminal point C. 

6. POWER SUPPLY CORD 

Connect one lead, terminal point E, one lead, terminal point D. 

7. COPPER WIRE 

Connect one end to terminal point F. one end terminal point B. 

DISCHARGE RESISTOR 
I 

I A 



r-^eOtlP 



z 







COPPER 
4> WIRE 

B 



INTERFERENCE 
SUPPRESSORS 



E 7) 

NOTE: CONDENSER (40 16 795) NOT SHOWN 



175 



WIRING DIAGRAM 

•MODELS 1040, 3240, 5540, 6440 

1060, 3260, 5560, 6260, 6360, 6460 
6170, 6270, 6370 

1. DISCHARGE RESISTOR (41 14 919) 
Connect leads, terminal point A and point B. 

2. INTERFERENCE SUPPRESSORS (41 14 920) 

Connect one suppressor between terminal point A and point E. Install second 
suppressor to terminal point B and point C. 

3. CONDENSER (41 14 911) 

Connect one lead, terminal point C, one lead, terminal point D. 

4. LAMP 

Route lamp wires over top of terminal board. Connect one lead, terminal point 
E, one lead, terminal point C. 

5. MOTOR 

Route motor wires through opening F. Connect one lead, terminal point E, one 
lead, terminal point D, 

*This diagram does not include grounded (earthed) models. 



DISCHARGE 
RESISTOR 



< INTERFERENCE 
I SUPPRESSORS 
I I 




CONDENSER 



176 



DISCHARGE 
RESISTOR 
\ 

\ 



INTERFERENCE 
SUPPRESSOR 

I 




H 




BOTTOM VIEW 
OF BED PLATE 



177 



WIRING DIAGRAM 

GROUNDED (EARTHED) MACHINES 
MODELS 1040, 3240, 5540, 6440 

1060, 3260, 5560, 6260, 6360, 6460 

6170,6270,6370 

1. DISCHARGE RESISTOR (41 14 919) 
Connect leads, terminal point A and point C. 

2. INTERFERENCE SUPPRESSOR (41 14 920) 

Connect one lead, terminal point C, one lead, terminal point F. 

3. CONDENSER {41 14 911) 

Connect one lead, terminal point C, one lead, terminal point D. 

4. LAMP 

Route lamp wires over top of terminal board. Connect one lead, terminal point 
F, one lead, terminal point C. 

5. MOTOR 

Connect one lead, terminal point F, one lead, terminal point D. 

6. GROUND WIRES (EARTH) 

Install green (earth) wire with uninsulated connector to motor frame point G. 

Connect other lead, terminal point B. 

Route green (earth) wire with uninsulated connector to motor frame point G. 

Connect other lead, terminal point B. 

Route green (earth) wire with red insulator through opening in bed plate E. 

Secure connector to bed plate, point H, with metal screw (23 23 294). Connect 

other lead, terminal point B. 

CAUTION: The wiring instructions for grounded machines must not be employed 
on standard terminal boards. 

These instructions apply to factory ground kits (49 36 000). For information 
regarding specific model application contact the nearest Viking Sewing Machines 
Co., Inc. Service Department. 



178 



FOOT CONTROL WIRING DIAGRAM 

CLASSES 8, 19S, 19A, 19E, 21, 21 A, 21 E, 2000 
MODELS 0210, 1010, 3010, 4010, 5010, 5210, 6010 

1. 185-OHM RESISTOR (40 16 476) 

Connect one lead, terminal point A, one lead, terminal point C. 

2. INTERFERENCE SUPPRESSOR (40 16 506) 

Connect lead with discharge resistor, terminal point C, connect other lead, 
terminal point B. 

3. CONDENSER (40 16 507) 

Connect one lead, terminal point A, one lead terminal point B. 

4. FOOT CONTROL CABLE 

Connect one lead, terminal point A, one lead, terminal point B. 



NOTE Ensure glass fiber insulation sleeves are installed on interference sup- 
pressor and condenser leads. 




CONTACT ROLLER 

40 16 478 



185 OHL RESISTOR 

40 16 476 



DISCHARGE 
RESISTOR 



INTERFERENCE < 
SUPPRESSOR 



^JJ 



CONDENSER f A 



179 




PRINTED IN THE USA Part No - 063 002